MONTREAL (AP) ― Top-ranked Novak Djokovic advanced to the Rogers Cup final when Jo-Wilfried Tsonga retired from their semifinal match Saturday night because of an apparent right arm injury.

Djokovic, who led 6-4, 3-0 when the Frenchman retired, will face sixth-seeded Mardy Fish on Sunday.

The Australian Open and Wimbledon champion is playing his first tournament since taking the top spot in the world rankings and improved his match record for the year to 52-1, including 28-0 on hard courts.

Djokovic, the Rogers Cup winner in 2007, is seeking his ninth tournament win of the year and his record fifth of the season in an ATP Masters event.

Tsonga, who took Djokovic to four tight sets in the Wimbledon semifinals, indicated to the chair umpire there was a problem with his arm after losing his first service game of the second set.

After Djokovic held serve, Tsonga was examined by a doctor at courtside and decided to stop playing.

Earlier, Fish advanced to his third straight ATP Tour final, beating Janko Tipsarevic 6-3, 6-4.

The American has won 11 of his last 12 matches, winning at Atlanta last month and reaching the final two weeks ago in Los Angeles. He’s trying to become the first American to win the Rogers Cup since Andy Roddick in 2003.

“I win a lot of matches because I can play a lot of different styles, I think,” Fish said. “A faster surface like this is going to suit my game perfectly ― a hard court where I’ve got my footing pretty good. My serve moves through the court well. You can come in. You can stay back a little bit, as well. But to be this successful, I have to play really well, too, and I’ve done that.”

Fish’s performance also helps his bid to be seeded high for the U.S. Open later this month. He has another tournament next week in Cincinnati before the Open.

“I desperately wanted to go into the U.S. Open in the top 10,” he said. “I’m not sure where this puts me now or if it moves me at all. At least it gives me a little cushion against some of the guys that are coming up.”

Serena Williams advances

TORONTO (AP) ― Serena Williams advanced to the final in the Rogers Cup, beating fourth-seeded Victoria Azarenka of Belarus 6-3, 6-3 on Saturday night.

The 29-year-old Williams, playing just her fourth tournament since being sidelined for a year by injuries and illness, will face 10th-seeded Samantha Stosur in the final.

“My goals have been just to give it my all at every match and every tournament,” Williams said. “Not that it wasn’t like that before, but I had a tremendous amount of focus in the Grand Slams, and I think I still will. But every now and then. ... you never know, tomorrow is not promised and I want to give it my all at every opportunity I have.”

Stosur beat Poland’s Agnieszka Radwanska 6-2, 5-7, 6-2.

Williams, the 13-time Grand Slam champion who isn’t seeded as she continues her comeback, put in her most dominant performance this week, winning in 1 hour, 17 minutes.

Dressed in an emerald green long-sleeved shirt and black skirt, her hair pulled back in a black headband, Williams was the clear crowd favorite at Rexall Centre stadium.

The match was her’s for the taking when she broke Azarenka’s serve on a double-fault to go up 4-3 in the second set. Williams carried all the momentum from that point on, eventually winning on a blistering shot to the back corner that Azarenka had little hope of getting to.

“I feel it’s better today than it has been the past couple of rounds, but I feel it’s coming along, I feel I can still do a little better but overall I’m almost where I was. Almost,” Williams said. “But I want to exceed that level.”

Williams was injured shortly after claiming her fourth Wimbledon title. A few days after that victory, she cut her foot on glass at a restaurant in Germany, and underwent two operations. She spent 10 weeks in a cast and 10 weeks in a walking boot. Then she was diagnosed in February with blood clots in her lung, and didn’t return to practice court in April.