Kei Nishikori and Stan Wawrinka will try to prevent what appears an inevitable Novak Djokovic-Roger Federer showdown at the ATP World Tour Finals in London.
A plethora of one-sided matches during the round-robin phase at London’s O2 Arena has resulted in the top four seeds reaching the semi-finals.
Federer and Nishikori booked their places from Group B on Thursday while, on Friday, Djokovic took his record to only nine games lost in three matches by beating Tomas Berdych 6-2 6-2 to secure the year-end world number one ranking.
That left Wawrinka needing just three games against Marin Cilic to finish in second spot, and he easily achieved the objective in a 6-3 4-6 6-3 victory.
Federer and Djokovic have looked a class apart so far but both will expect sterner tests on Saturday.
Djokovic takes on Nishikori, who has been by far the best of the debutants, and the two-time defending champion needs no reminder of how dangerous the Japanese player can be.
Nishikori pulled off one of the most stunning results of the season by upsetting Djokovic in the semi-finals at the US Open, although the Serbian did win comfortably in Paris two weeks ago.
“It’s obvious that he’s experiencing the best season of his life,” said Djokovic. “He’s in the top five of the world. He’s playing some great tennis. He’s one of the quickest players around. Deservedly he’s in the semi-finals on his debut.
“I expect a tougher match than it was in Paris, that’s for sure. The conditions where I lost to him at the US Open are quite different. I’m feeling pretty confident playing now, as is he. So it’s going to be good, high-class tennis.”
Nishikori has an excellent record against top-10 rivals this year while no one has a better winning percentage in third sets.
He said: “Rafa (Nadal), Roger and Novak are a little bit ahead of the top-10 guys. But I think we’re getting close.
“I’ve been beating them a couple of times, so I think I have a little more experience. If I learn how to win against them, I think I can be really, really close to them.”
Wawrinka made the semi-finals on his debut 12 months ago, losing to Djokovic, and this time it is his good friend Federer who will be across the net.
The pair will team up next weekend for Switzerland’s Davis Cup final against France and Federer thinks it can only bode well for both of them to be in the last four.
Speaking before Wawrinka’s progress was confirmed, he said: “If we play each other, it’s a good thing that one of us is going to go to the final.
“It’s an extra match for Stan, in particular. It’s an opportunity for both of us to play a quality match ahead of Davis Cup.
“But we care about playing very well here. I’m very happy I’m getting to play an extra match because I want to arrive in France with a lot of matches in my legs. I wouldn’t want it any other way.”