Rafael Nadal ignored an opening set knee injury worry to reach his first Swiss Indoors final with a 6-4, 7-6 (9/7) defeat of Richard Gasquet on Saturday.

The Spanish third seed admitted he got a fright when he felt something in his right knee after a sudden movement in the seventh game.

He immediately called for the trainer and got a strapping below his kneecap before carrying on.

Nadal then resumed business as usual with a break-back of Gasquet for 4-4 on his way to taking the set on a third winning opportunity with an inside-out forehand winner.

"I was a little bit scared, I felt something in the knee," he said. "It's not the knee I usually have problems (with)."

Nadal will play either Roger Federer or American outsider Jack Sock in Sunday's final in Basel.

Top seed Federer is bidding for a seventh title at his hometown event.

Nadal went down an early break in both sets and had to battle in the second set after winning the first.

Gasquet broke for 1-0, taking seven break points to finally earn a lead. Nadal then resumed his battle to catch up finally getting that break back for 5-5.

Gasquet put over an ace to send the set to a tiebreaker, where he trailed 4-1 before catching up.

But he missed on a set point with a low return which proved to be a fatal error with Nadal riding out the win on his second match point on a Gasquet error.

Gasquet's defeat also settled the field for the eight-man World Tour Finals in London from November 15, with Japan's Kei Nishikori and David Ferrer of Spain taking the last two spots.

Federer, Nadal, world number one Novak Djokovic, Andy Murray, Stan Wawrinka and Tomas Berdych make up the eight-man field.

"I am very excited to qualify for London for the second year in a row," Nishikori wrote on Facebook.

"It’s always a big goal at the beginning of the year to make it to London so I am proud of the year I am having so far.

"Last year there were was a lot of support and I am really looking forward to coming back to the O2 Arena."

Source: AFP