Roger Federer downed Karen Khachanov 6-3, 7-6 (8) in the 2018 Hopman Cup on Tuesday as Switzerland beat Russia in Group B to move within one win of the final.
The world No. 2 produced a typically serene display against 21-year-old Khachanov and saw out the match with great composure in the second-set tiebreak after a fine effort from his opponent.
Belinda Bencic then edged Anastasia Pavlyuchenkova in a tight three-setter, prevailing 6-1, 3-6, 6-3 to see Switzerland to victory with the mixed doubles still to play.
Earlier on Tuesday, the United States earned their second victory of the tournament as they benefitted from the withdrawal through illness of Japan's Naomi Osaka.
Osaka was replaced by 19-year-old Maddison Inglis in order for play to go ahead, but the U.S. were awarded straight-sets victories in the matches she was set to be involved in: the women's singles and mixed doubles.
As a result, there was no way for Japan to earn a victory, but Yuichi Sugita did prevail in the men's singles when Jack Sock was forced to retire while trailing 7-6 (1), 1-1:
Hopman Cup @hopmancup
#TeamJapan's Yuichi #Sugita claims the win against Jack Sock. The American was forced to retire with an injury after dropping the first set in a tiebreak. #HopmanCup https://t.co/UwA69LGaAn2018-1-2 05:16:29
Federer, 36, looked in fine form in his clash with Khachanov. The towering Russian's serve and power are his main weapons, but Federer's returning was impressive enough to effectively neutralise the threat.
The Swiss legend was broken in the first game of the match but responded by winning four games on the bounce as he moved Khachanov back and forth across the court with impeccable positioning.
There was no way back for the youngster in the opening set, but he did find enough composure to hold two service games. He then made Federer work hard to win the match in straight sets, twice making the Swiss serve to stay in the second before it went to a tiebreak.
The breaker was just as tight as the set that had preceded it, with both players producing some eye-catching touches at the net. Khachanov saved the first match point Federer earned before then getting a set point of his own as he attempted to level the clash.
As so often with Federer, though, he kept his nerve, drew level again and then sealed the match at the second time of asking.