Pete Sampras shocked world number one Roger Federer in Macau on Saturday to pull back to 2-1 in their Asian exhibition series.
The former US world champion forced the first break of the match at 4-4 in the second set and served out for victory.
He had earlier taken the first set on a tie-break 10-8 after a tight affair in which there were no breaks of serve.
Sampras started the match strongly with his trademark heavy serve firing, hitting two aces in the first game and never letting up. Both players hit 14 aces during the match.
Sampras impressed at the net with his serve-volley game, winning 14 points at the net to Federer's six.
Serve continued to dominate at the start of the second set with neither player able to force the vital break. Federer pushed Sampras to deuce in game eight, but the US player produced an ace to get out of trouble and level it up at 4-4.
Their clash in the packed arena at Macau's Venetian resort was their third match in just five days, following meetings in Seoul and Malaysia.
Federer won the first match played in Seoul on Tuesday 6-4, 6-3 in 61 minutes.
The second clash, in Kuala Lumpur, was a closer affair over 90 minutes, with the 26-year-old Federer running out as the winner after winning both sets on tie-breaks.
The two met only once on the ATP Tour, in the fourth round of Wimbledon in 2001, when Federer defeated the American in five sets.
The loss ended Sampras' remarkable reign at the All England Club. Sampras, now 36, retired from professional tennis in 2002.