Arsenal relied on a late own-goal to draw 1-1 at Manchester United in the Premier League on Sunday and stay in control of the race for automatic qualification for the Champions League.
A cross by Theo Walcott in the 82nd minute deflected off the outstretched boot of United substitute Tyler Blackett and looped over wrong-footed goalkeeper Victor Valdes, who had just come on for his debut.
Ander Herrera gave United the lead in the 30th when he met Ashley Young's cross with a side-footed volley, but the hosts were pinned back for much of the second half at Old Trafford.
Arsenal stayed third, two points ahead of United, and will secure a finish in at least that position by beating Sunderland in its game in hand on Wednesday. The last round of the Premier League is on Sunday.
Both Arsenal and United have already qualified for the Champions League but United is likely to need to go through qualifying to reach the lucrative group stage of Europe's top competition — and that could mean a match against the likes of Valencia, Monaco or Shakhtar Donetsk. To definitely avoid that prospect, Louis van Gaal's team must beat Hull away in its final game and hope Arsenal loses its last two, which are both at home.
Arsenal is still without a win at Old Trafford in the league since 2006, but will be pleased by its second-half performance after a poor first 45 minutes when the team failed to take a single shot. That hasn't happened in a league game for Arsenal since November 2004.
There was little between the sides early on and it needed a moment of quality from Young to break the deadlock. The winger was United's most dangerous attacking outlet and he sent over a superb cross which was met with a volley by Herrera inside the near post.
United goalkeeper David de Gea, who hobbled off with an apparent hamstring injury in the 74th to be replaced by Valdes, was called upon for the first time when he kept out a close-range poke by Olivier Giroud in the 63rd.
By that time, Radamel Falcao had been substituted — and a little wave to the United crowd as he made his way to the dugout suggested this could be the last Old Trafford sees of him. The Colombia striker is on loan from French club Monaco and has scored four goals in 28 games — and not since Jan. 31.
Arsenal continued to press and it needed a timely intervention from Marcos Rojo to deny Aaron Ramsey, who had lobbed the ball past De Gea toward an open goal.
That was De Gea's last meaningful action. Like Falcao, De Gea's future at Old Trafford is in doubt amid reports linking him with Real Madrid.
Valdes came on to applause and had only touched the ball a few times when he had to pick it out of the net after Blackett's unfortunate deflection. The goal makes Arsenal big favorite for third and the team could yet catch Manchester City, which is five points ahead in second.
Wilfried Bony scored on his return to former club Swansea to cap Manchester City's 4-2 win in the Premier League on Sunday that guaranteed the team a place in the group stage of the Champions League next season.
Bony, who joined City in January for an initial fee of 25 million pounds (now $39 million), came on as a substitute and rounded off an impressive attacking display by the deposed champions by scoring in stoppage time.
Yaya Toure scored the first of his two goals at Liberty Stadium in the 21st minute before James Milner made it 2-0 in the 36th.
Swansea drew level thanks to goals from Gylfi Sigurdsson and Bafetimbi Gomis, only for City to strike through Toure and Bony to seal a top-three finish.
City is eight points clear of fourth-place Manchester United, which has two games left, after winning its last five games.
Bony didn't celebrate after slotting home a finish from the edge of the area that hit the post and crawled across the line and into the net. It was his second goal for City since joining after 1 ½ years at Swansea, where he was one of the Premier League's leading scorers.
Earlier, it had been Bony's Ivory Coast teammate Toure who had made the headlines with a double that showed just what City would be missing if he moves at the end of the season, as is being widely reported.
Toure made his way into the area and slammed a shot inside the near post for a goal that Swansea goalkeeper Lukasz Fabianski could have stopped. Milner ran onto Sergio Aguero's pass, cut inside and then curled in a shot past Fabianski.
Swansea always looked dangerous going forward, though, and Sigurdsson reduced the deficit in the 45th by firing in from the edge of the box. Gomis then brought down a long pass and scored with a diagonal finish in the 64th.
Fabianski saved well from David Silva and Aguero, only to let another shot from Toure squirm past him in the 74th.
City goalkeeper Joe Hart produced two fabulous saves before Bony's goal sealed the three points.