MADRID — World No. 1 Novak Djokovic reached the final of the Madrid Open after seeing off last year's runner-up Dominic Thiem 7-6(7-2) 7-6(7-4) in a grueling, high-quality encounter on Saturday that lasted two hours and 22 minutes.

The Serbian will meet either five-time Madrid champion Rafael Nadal, the world No. 2, or Stefanos Tsitsipas in Sunday's final after producing his best tennis since winning the Australian Open in January.

Djokovic, winner in Madrid in 2011 and 2016, was fully rested after his quarter-final opponent Marin Cilic had withdrawn because of food poisoning, while Thiem had to dig deep to beat Roger Federer in a grueling three-setter.

Thiem, who had won the Barcelona Open last month and was on an eight-match winning streak, struck an early blow by breaking Djokovic in the fourth game but the Serbian responded by winning the next three games and saved two break points in the eighth.

The Serbian won the first tiebreak comfortably after some poor shot selections from Thiem but was in trouble in the second set when he trailed 4-2.

He immediately broke back and had the chance to serve for the match at 6-5 but squandered the opportunity with a double fault.

Yet once again Djokovic had the edge in the tiebreak, earning three match points and taking the first one as Thiem smashed a baseline backhand well out, booking his place in a first final since winning the Australian Open.

On late Friday, Nadal beat Stan Wawrinka 6-1, 6-2 to set up a clash with Tsitsipas, who edged Alexander Zverev 7-5, 3-6, 6-2, in the other semi.

Nadal made light work of Wawrinka in the night session, looking back to his best after a disappointing semifinal exit at the Barcelona Open and suffering a virus earlier this week.

A five-times winner in Madrid, Nadal reached the semifinals for the 11th time when Wawrinka's attempted backhand return hit the net. "It was one of my best games for some time," said Nadal.

Tsitsipas played a steady game to beat last year's winner Zverev, who made 14 unforced errors in the opening set. Zverev roared back in the second but double faulted twice serving at 1-2 down in the decisive third, with Tsitsipas breaking and striding to victory in the battle between two of the sport's young talents.

"I think I deserved the match at the end. I was playing really well, feeling really comfortable on the court," said Tsitsipas. "When you feel like this, you can do miracles." — Reuters