PARIS, Nov. 4 -- Serbian qualifier Filip Krajinovic recorded his first ATP Masters 1000 final at the Paris Masters here on Saturday, while Jack Sock of the United States maintained his hope of reaching the season-ending finale in London later this month.

Following several top seeds' early exit from the tournament, Saturday's semifinals featured four players attempting to capture their first career ATP Masters 1000 title.

Krajinovic withstood 31 aces from John Isner of the United States, also in quest for a Finals berth, and made his breakthrough in full sets after nearly two and a half hours.

Krajinovic took away the first set at 6-4. The two players held their serves in the first 12 games of the second set, before Isner forced into a decider as he won the tie-break 7-2.

In a quite similar decider, Isner kept himself in the match with his signature services against Krajinovic's solid baseline performance. It was the Serbian that secured a final spot after uppering in another tie-break 7-5.

"It was a tough mental match. He was serving really well, and playing aggressive. I knew that was going to happen.

"When I served for the match, my hand was shaking. It was tough to control the emotions, but I knew I had to stay aggressive all the way to the end, and I did it. It's the best day in my life," said Krajinovic, who is projected to break the top 50 in the ATP Rankings.

Isner had to come to a stop on his way to the ATP Finals, scheduled on November 12-19.

"Very, very disappointing," admitted Isner. "I had an opportunity here to do some things that I've never done before, finish in the top 10 in the world. I mean, it's very good. It's consistent."

"You can say either it's not good or it's really good," added Isner, last year's runner-up behind Andy Murray.

Isner's fellow American Sock continued his own dream of clinching the Finals spot, as he saw off home favorite Julien Benneteau 7-5, 6-2.

Sock, coming in this week No. 24 in the ATP Race to London, could overtake Spain's Pablo Carreno Busta and secure last spot of the Finals if he won the title on Sunday.

"I was able to go out today and play my game, swing big, play some good tennis and get through. Tomorrow is just a good opportunity for me to go out and try to compartmentalize all the things that would come with winning tomorrow, just go out and play my tennis again," he said.

Benneteau, 35, overcame Jo-Wilfried Tsonga, David Goffin and Marin Cilic en route to the semifinals. He received lopsided support from crowds in the AccorHotels Arena, but it seemed that in the second set, he ran out his energy against Sock, who is 10 years younger than him.

"He hurt me from the start with certain rallies where he was controlling the point with his forehand. He was better than I was in all parts of the match," commented the Frenchman.

PARIS, Nov. 4 -- Serbian qualifier Filip Krajinovic recorded his first ATP Masters 1000 final at the Paris Masters here on Saturday, while Jack Sock of the United States maintained his hope of reaching the season-ending finale in London later this month.

Following several top seeds' early exit from the tournament, Saturday's semifinals featured four players attempting to capture their first career ATP Masters 1000 title.

Krajinovic withstood 31 aces from John Isner of the United States, also in quest for a Finals berth, and made his breakthrough in full sets after nearly two and a half hours.

Krajinovic took away the first set at 6-4. The two players held their serves in the first 12 games of the second set, before Isner forced into a decider as he won the tie-break 7-2.

In a quite similar decider, Isner kept himself in the match with his signature services against Krajinovic's solid baseline performance. It was the Serbian that secured a final spot after uppering in another tie-break 7-5.

"It was a tough mental match. He was serving really well, and playing aggressive. I knew that was going to happen.

"When I served for the match, my hand was shaking. It was tough to control the emotions, but I knew I had to stay aggressive all the way to the end, and I did it. It's the best day in my life," said Krajinovic, who is projected to break the top 50 in the ATP Rankings.

Isner had to come to a stop on his way to the ATP Finals, scheduled on November 12-19.

"Very, very disappointing," admitted Isner. "I had an opportunity here to do some things that I've never done before, finish in the top 10 in the world. I mean, it's very good. It's consistent."

"You can say either it's not good or it's really good," added Isner, last year's runner-up behind Andy Murray.

Isner's fellow American Sock continued his own dream of clinching the Finals spot, as he saw off home favorite Julien Benneteau 7-5, 6-2.

Sock, coming in this week No. 24 in the ATP Race to London, could overtake Spain's Pablo Carreno Busta and secure last spot of the Finals if he won the title on Sunday.

"I was able to go out today and play my game, swing big, play some good tennis and get through. Tomorrow is just a good opportunity for me to go out and try to compartmentalize all the things that would come with winning tomorrow, just go out and play my tennis again," he said.

Benneteau, 35, overcame Jo-Wilfried Tsonga, David Goffin and Marin Cilic en route to the semifinals. He received lopsided support from crowds in the AccorHotels Arena, but it seemed that in the second set, he ran out his energy against Sock, who is 10 years younger than him.

"He hurt me from the start with certain rallies where he was controlling the point with his forehand. He was better than I was in all parts of the match," commented the Frenchman.