Novak Djokovic will attempt to become the first player to win all nine Masters 1,000 tournaments when he faces Roger Federer in Sunday's Cincinnati Masters final.
The Serb, a five-time runner-up at the event, beat Marin Cilic of Croatia 6-4 3-6 6-3 in his semi-final.
Federer's opponent, Belgian David Goffin, retired with a shoulder injury, reports BBC.
The Swiss had taken the first set of the last-four tie 7-6 (7-3) and it was 1-1 in the second when Goffin withdrew.
Federer, a seven-time champion in Cincinnati, will be playing in his 150th final - and the 37-year-old world number two is looking for his 99th win.
The match is scheduled for 02:00 Bangladesh time.
Djokovic leads their head-to-head 23-22, but Federer has won all three of their Cincinnati final meetings.
"Obviously this time I'm hoping that I can get my hands on the trophy," said Wimbledon champion Djokovic, 31.
"History is also on the line and I'm aware of that and that motivates me even more."
The 13-time Grand Slam champion - ranked 10th in the world - needed two hours and 32 minutes to beat 2016 winner Cilic.
Djokovic won just eight points on his return in the first set, but breaking Cilic's serve in the third game before twice saving break point gave him the momentum to take the early advantage.
Cilic controlled the second set, taking a 5-1 lead with two breaks before Djokovic momentarily came back into the set - but at 5-3 the Croat held to love to send the match into a decider.
The semi-final swung in Djokovic's favour then, however, when he broke Cilic for 5-3 before serving for victory.
Federer said he had got to bed at 3:30am before facing Goffin, after his quarter-final against compatriot Stan Wawrinka finished at midnight.
"This is a big match," said the 20-time Grand Slam winner. "We're all a bit mentally and maybe physically tired - but I'm looking forward to this final. There's also a lot at stake for me. I'm going for my 99th title.
"I'm tired. I'm going to recover for tomorrow and hopefully be in better shape."
In the men's doubles final, Britain's Jamie Murray and his Brazilian partner Bruno Soares will face Colombian pair Juan Sebastian Cabal and Robert Farah at 17:15.
Murray and Soares, former Australian Open and US Open champions, are attempting to win their maiden Masters 1,000 title.
