Stan Wawrinka is braced for his showdown against world number one Andy Murray as he looks to advance to the semi-finals of the ATP World Tour Finals.
Swiss third seed Wawrinka kept his hopes alive with a 7-6 (7-3) 7-6 (7-3) victory over Marin Cilic, who consequently bowed out of the season-ending competition on Wednesday.
Wawrinka will now meet Murray - who leads 9-7 in their head-to-head record - in his final round-robin Group John McEnroe fixture, with the US Open champion eyeing a spot in the semis at the O2 Arena.
"All I know is if I want to have a chance to qualify, I need to win," said Wawrinka. "That's all I'm trying to do. I'm going to try to play my best tennis, to beat the World No. 1. It's going to be a tough match.
"We played many times against each other. He's playing his best tennis so far. It's going to be interesting.
"I'm happy to play here in front of his home crowd. I'm sure it's going to be a great atmosphere."
Wawrinka - who lost to Kei Nishikori in his first match - battled hard against the seventh-seeded Cilic in London.
After fending off a set point in the 10th game, Wawrinka's powerful groundstrokes saw him pull clear in the tie-break.
There was not much to separate the two players in the second set as another tie-break was required, with Wawrinka emerging triumphant after one hour, 58 minutes.
"It was a great match," said Wawrinka. "I'm really happy with the way I played in general. It was a tough match, for sure - two tie-breaks.
"I think the level was really high... I think I was moving great. It was a great victory for me."
Cilic - 0-2 in group play this year - added: "In the first set, I obviously had a set point. A second serve, I missed the return there. In the tie-breaks, I felt I lost a couple points that I could have won as well. Just few points that went on his side could also have gone to my side."