Cristiano Ronaldo scored twice for Real Madrid to beat Bayern Munich 2-1 in the first leg of their Champions League quarterfinal on Wednesday, ending the German side's tournament record of 16 straight wins at home.

Ronaldo's second-half goals saw him become the first player to score 100 goals in European club competition. The Portuguese star ensured Madrid came from behind - after Arturo Vidal's 25th-minute header for Bayern - to put the defending champions on course to reach the semifinals for a seventh successive year. The second leg takes place in Madrid on Tuesday.

"We are still alive," said Bayern coach Carlo Ancelotti after losing to his former side.

Also Wednesday, Antoine Griezmann converted a first-half penalty for Atletico Madrid to beat Leicester 1-0 at home, and Borussia Dortmund lost 3-2 at home to Monaco in the quarterfinal that was rescheduled from Tuesday, when three explosions targeted the German team's bus.

Bayern was without club top-scorer Robert Lewandowski after he failed to recover from a knock to his right shoulder. But it had not been beaten at home in the competition since April 2014, when it lost 4-0 to Ancelotti's Madrid in the semifinals. Madrid went on to win the title.

Ancelotti's successor at Madrid, Zinedine Zidane, is bidding to become the first coach to lead a side to back-to-back titles in the Champions League era.

"We suffered here but all-in-all it's not easy to play here. They have a great team and great players," Zidane said. "We needed patience to decide the match. I think it's a good result for us. The key was patience."

Bayern forced several corners early on and the sixth finally paid off when Vidal headed home through Keylor Navas' fingers.

Madrid displayed none of the initiative shown by Bayern in the first half. While Arjen Robben, Franck Ribery, David Alaba and Thiago Alcantara were running and forcing the game, the visitors appeared static, waiting for chances to present themselves. They weren't forthcoming.

Bayern should have been 2-0 up at the break, but Vidal sent his penalty well over the bar after Dani Carvajal was adjudged to have handled the ball. The Madrid defender was booked though TV replays showed Ribery's shot had hit his upper body.

"It happens in football. It's not the first time and it won't be the last," Ancelotti said of the missed penalty, calling it one of the "small details" which decided the game.

Ronaldo scored two minutes after the break with one touch to Carvajal's cross.

It ensured Madrid extended its Spanish record of scoring in 53 consecutive games.

Zidane had evidently made good use of the interval as Madrid appeared a different side in the second half. Bayern was dealt a blow with a half-hour to play when Javi Martinez was sent off with two yellow cards within three minutes for fouls on Ronaldo.

"The sending off was the turning point," Bayern captain Philipp Lahm said.

But Madrid had already forced the home side back. Navas had little to do and Manuel Neuer was by far the busier 'keeper.

"Their goalkeeper saved lots of chances. A lot," Zidane said of Germany's top 'keeper.

Marco Asensio's introduction for Gareth Bale also invigorated the visitors.

Neuer denied Karim Benzema, then Ronaldo from point blank, but he couldn't stop the ball from squirming between his legs from Ronaldo's shot after Asensio crossed in the 77th to give Madrid the clear advantage.

It could have been worse for Bayern - Sergio Ramos had a goal ruled out late for offside.

Borussia Dortmund lost its rescheduled Champions League quarterfinal with Monaco 3-2 on Wednesday after tributes were paid to the player injured when three explosions targeted the German team's bus.

Teammates of Marc Bartra, who underwent surgery for injuries to his wrist and arm after Tuesday's attack, wore T-shirts emblazoned with the defender's picture and a message in Spanish saying: "A lot of strength - we are with you."

And Dortmund didn't let the Spaniard down on the field despite losing the first leg, which was originally due to be played on Tuesday.

"It was very difficult for the team to focus on the game," Dortmund coach Thomas Tuchel said. "But we noticed that training did us good."

Far from capitulating against one of Europe's high-scoring sides, for whom Kylian Mbappe scored twice, Dortmund fought back to deny Monaco a commanding lead to take into the second leg.

"Of course it affected everyone on our team," Dortmund winger Christian Pulisic told British broadcaster BT, sidestepping questions about whether the game should have gone ahead so soon after a traumatic incident.

"Today was the day that the game was and we had to play it. So we tried to go out and I'm still proud of us for being strong and going out and playing regardless."

There was an early reprieve for the hosts when Fabinho missed a penalty after Mbappe was held back. And it was a fortuitous opener from Mbappe in the 19th minute, with Thomas Lemar's cross deflecting off his knee and going into the net.

But Lars Bender, the midfielder who replaced Bartra in the starting lineup and deployed as a makeshift defender, was left red-faced when he headed Andrea Raggi's cross into his own net in the 35th minute for 2-0 to Monaco.

Dortmund made two changes at halftime and the impact was immediate, with a high tempo opening to the second half. Christian Pulisic unsettled the visitors with his runs and fellow substitute Nuri Sahin instigated a wonderful team move that ended with Ousmane Dembele scoring.

Sahin surged forward before working the ball out to the left flank. Raphael Guerreiro then crossed to Pierre-Emerick Aubameyang, who knocked the ball forward for Shinji Kagawa to square to Dembele to tap into the net.

There was another moment of misfortune in the Dortmund defense in the 79th when Lukasz Piszczek's sloppy back pass to Sokratis Papastathopoulos was intercepted by Mbappe who knocked in his 19th goal of the season.

Dortmund responded within five minutes, with Sahin whipping the ball into the penalty area and Kagawa turning Jemerson before slotting into the net.

The game took place amid heightened security after a review of the policing operation by authorities in Germany and Spain at all three Champions League games on Wednesday. In Munich, Bayern lost 2-1 to Real Madrid while in the Spanish capital Atletico Madrid beat English champion Leicester 1-0.

Three explosions went off near the bus carrying Dortmund's team to the stadium on Tuesday just after it left a hotel, blowing in a window at the back and shards of glass struck Bartra.

After an operation, Bartra on Wednesday posted a photo of himself online with a bandage wrapped around much of his right arm, and a smaller bandage around his left wrist. The center back made a thumbs-up gesture with his left hand and wrote on Instagram that he's "doing much better."

Dortmund said Bartra won't be able to play for several weeks.

Antoine Griezmann converted a first-half penalty kick to give Atletico Madrid a 1-0 win over Leicester in their first leg of the Champions League quarterfinals on Wednesday, keeping the Spanish club on track to make it to the final for a second straight season.

Griezmann coolly scored from the spot in the 28th minute by sending goalkeeper Kasper Schmeichel the wrong way with a firm strike into the left corner.

The penalty came after Griezmann was clipped by Leicester defender Marc Albrighton after making a long run down the left flank. Griezmann appeared to be still outside the area when he was fouled.

"We played a very good game," Atletico coach Diego Simeone said. "Maybe we needed to be a bit more aggressive to get a better result, but we have to understand that even after going down a goal our opponent stayed playing tightly on defense. They were clearly looking to take that result to the second match."

Simeone's Atletico is trying to reach the semifinals for the third time in four seasons, while Leicester - the shock Premier League winner last season - is looking to make another stunning title run in its debut in the Champions League.

"To come here and still be in the game was the main objective," Leicester midfielder Andy King said. "We know we are strong at home and I am sure we can cause them problems."

The second leg takes place Tuesday in England.

Atletico was in control from the start at the Vicente Calderon Stadium, creating several scoring chances while restraining Leicester. The hosts had three clear opportunities less than 15 minutes into the match, with Koke striking the right post with a long-range shot as early as the fourth minute.

Leicester had no attempts on target for the entire game. The visitors played better in the second half than the first but still couldn't create any significant danger to the Atletico defense.

"We are still alive," Leicester manager Craig Shakespeare said. "But we know we still have a challenge ahead against a very good team. We have a very good record at (home), the fans really enjoy these Champions League nights, although we know we'll have to create more chances than we did tonight."

Shakespeare criticized the penalty decision.

"It was one of the major decisions in the game," he said. "It was definitely a foul, but it was outside the box."

The penalty came as fans were still loudly celebrating the announcement that Bayern Munich had just opened the scoring against city rival Real Madrid in Germany. The defending European champions were able to mount a comeback, though, winning 2-1 with a pair of goals by Cristiano Ronaldo.

Griezmann had already been decisive when he scored a late equalizer against Madrid in the teams' 1-1 draw in the Spanish league over the weekend at the Santiago Bernabeu Stadium.

Wednesday's win extended Atletico's unbeaten run in all competitions to nine matches. It has conceded only two goals in its last eight games.

Atletico has won 29 of its last 35 games in European competitions at the Vicente Calderon.

It was the second consecutive loss for Leicester, which had been thriving since Shakespeare replaced Claudio Ranieri after a struggling start to the season. The English club won six straight games until a league loss at Everton on Sunday, when several regular starters were rested.

Atletico lost last year's Champions League final in a penalty shootout against Madrid. It also fell to the city rival in the final three seasons ago, and was eliminated by Madrid in the quarterfinals in 2014-15.

Leicester eliminated Spanish club Sevilla in this season's Round of 16.