Japan's Yoshihito Nishioka battled Felix Auger-Aliassime and his own emotions through three topsy-turvy sets Monday to grab a 6-7 (2/7), 6-4, 7-6 (7/5) victory in the ATP Indian Wells Masters.
Trailing the 18-year-old Canadian by a set and a break, Nishioka roared back, winning five of the last six games of the second set and streaking to a 5-1 lead in the third.
But Auger-Aliassime, whose second-round upset of Stefanos Tsitsipas was his first over a top-10 foe, fought back to level the set, saving three match points as he forced the tiebreaker.
He was up 5-3 in the tiebreaker, but Nishioka's consistency made the difference and the 23-year-old emerged with the victory after two hours and 56 minutes.
"It's very tough to play in that situation," Nishioka said. "It was feeling so tight and feeling very mad when he came back because I had a chance to win already - three times match point.
"But he saved them with really good shots... I just tried my best and I found a way, finally."
Auger-Aliassime, who reached the final in Rio last month, came out firing from the baseline, doing most of his damage off his forehand.
But more errors crept in late in the second set and he began to look a little weary.
"He just started playing high on my backhand. I wasn't hitting as many forehands. I was struggling to dictate the points, struggling to move, the serve, as well. From there, it was tough," Auger-Aliassime said. "He was really dominating."