Red Bull driver Daniel Ricciardo won an incident-packed Belgian Grand Prix on Sunday, while Nico Rosberg was second to extend his championship lead over Mercedes teammate Lewis Hamilton in acrimonious circumstances.

Finnish driver Valtteri Bottas was third.

The increasingly strained relations at Mercedes look set to get even worse after Rosberg effectively ended Hamilton's race chances with a risky overtaking move that saw him clip and puncture the Briton's left tire.

Rosberg, who finished 3.3 seconds behind Ricciardo, was jeered by the Spa crowd when he stepped on to the podium.

"It's not my position to comment on it at all because I haven't seen it," Rosberg said of the incident. "Of course it's very disappointing from a team's perspective. We could have done a lot better than just finish in second place with the car we have."

Hamilton retired with five laps remaining after his team noticed some further degradation and he appeared to blame Rosberg after the race.

"I'm sure he'll leave here happy," Hamilton told the BBC.

Mercedes executive director Toto Wolff called the situation "absolutely unacceptable" and blamed Rosberg.

"You don't try to overtake with the knife between your teeth in lap number two and damage both cars," he told BBC sport. "Lewis is very upset. We kept him out there for a long time with a damaged car. He will recover quickly. It is going to be handled."

Rosberg looked visibly uncomfortable in the post-race news conference when asked to respond to Wolff's comments.

"I respect their opinion," Rosberg said. "The inside was blocked and I gave it a go on the outside."

It was a second straight win for Ricciardo after victory at the Hungarian GP last month and the third of an impressive season. The Australian continues to outshine his Red Bull teammate Sebastian Vettel, who finished fifth behind Ferrari's Kimi Raikkonen.

"To have three wins in 12 races has exceeded a few expectations. The in-team battle has gone really well," Ricciardo said. "I've shown speed throughout qualifying and in the race now. I've demonstrated race craft and good consistency."

Rosberg extended his lead over Hamilton from 11 points to 29, while Ricciardo is 35 points behind Hamilton. Showing remarkable consistency, Bottas secured a fourth podium in the past five races.

Rosberg started from pole for the fourth straight race, but Hamilton and Vettel got past the German on turn 1.

Then, as Hamilton fixed his racing line, Rosberg tried to pass him on the outside but his front wing hit Hamilton's left side, also damaging Rosberg's car.

"Nico hit me, Nico hit me," an exasperated Hamilton said over the race radio.

The two drivers have clashed throughout the season.

In Hungary, Hamilton refused team orders to let Rosberg past.

At the Monaco GP in May, Hamilton was incensed when Rosberg surprisingly crashed late in qualifying when under no pressure, leading to a safety car coming out and squandering Hamilton's chances of securing pole position.

Still, Rosberg is optimistic the situation will be resolved.

"I'm confident that we can. It's always going to be an intense battle and there will always be difficult moments. I'm sure we're going to have to discuss today," he said. "We had a very good discussion after Hungary. It was reviewed and clarified."

Hamilton had qualified on the front row for the first time in six races.

But once again the 2008 champion needed to carve his way back through the field, just like in the previous two GPS — Hungary and Germany — where he qualified 20th and 22nd due to technical problems.

Rosberg's front wing was replaced on lap nine. Then, in a bizarre turn, some flying debris got attached to the radio aerial on the front of the car and flapped around in front of his face. He tried in vain to remove it after at one stage the string-like material even caught on the steering wheel.

"A big piece of ... don't know what it was. I couldn't get rid of it, either," Rosberg said. "It eventually came off. I couldn't even see where I was going sometimes."

Hamilton had other worries, asking "Is my pace really far off?"

After 15 laps, Rosberg was fourth, with Vettel, Raikkonen and Ricciardo in front.

Two laps later, Rosberg failed to overtake Vettel in a move that ended with the Mercedes driver locking his wheels as smoke billowed from his front left tire.

Halfway through the 44-lap race, Hamilton asked his engineers if it would be better to retire and save the engine and then complained about having no downforce on his car. But he was told to scrap for points.

Things got intense in the battle for fifth, as two-time champion Fernando Alonso failed to get past Denmark's Kevin Magnussen on lap 38 and finished eighth.

Others also had trouble on the 7-kilometer (4.3-mile) track nestled in the Ardennes forest, with Jules Bianchi's left rear wheel flying off his Marussia after contact on the first corner.