Andy Murray booked his spot in the quarter-finals of the 2019 China Open after beating fellow Brit Cameron Norrie 7-6 (6), 6-7 (4), 6-1 on Wednesday in Beijing.
In a major test of his ongoing fitness after hip surgery, Murray was taken the distance by Norrie.
The former world No. 1 looked to be fading in the second set, and Norrie made it count with some fine play, especially in the tiebreak.
But Murray found a second wind and was brilliant in the third, eventually closing out victory in just under three hours.
The Scot goes on to face top seed Dominic Thiem next. The Austrian beat local favourite Zhizhen Zhang in straight sets to progress to the last eight.
In the women's draw, top seed Ashleigh Barty needed three sets and over two-and-a-half hours to beat China's Zheng Saisai, while world No. 15 Madison Keys was ousted by fellow American Jennifer Brady in the second round.
China Open, Selected Wednesday Results
Andy Murray bt. Cameron Norrie: 7-6 (6), 6-7 (4), 6-1
(4) Karen Khachanov bt. Jeremy Chardy: 7-6 (0), 7-6 (5)
(6) Fabio Fognini bt. Andrey Rublev: 6-4, 6-4
(1) Dominic Thiem bt. Zhizhen Zhang: 6-3, 6-3
(1) Ashleigh Barty bt. Zheng Saisai: 6-3, 6-7 (5), 6-2
Jennifer Brady bt. (11) Madison Keys: 2-6, 6-4, 6-4
(5) Bianca Andreescu bt. Elise Mertens: 6-3, 7-5 (5)
(7) Petra Kvitova (9) Belinda Bencic: 6-3, 6-3
(8) Kiki Bertens bt. Polona Hercog: 7-6 (8), 2-6, 6-3
For the full results and draw, visit the competition website.
Murray took a huge step in his comeback from injury on Tuesday by beating No. 8 seed Matteo Berrettini in the first round:
Wednesday's clash with Norrie was a different kind of test as he was widely expected to win, but the victory for Murray was similarly impressive, not least as he proved his fitness in another lengthy match:
The Scot took a tight first-set tiebreak after he and Norrie exchanged breaks in the opener.
But it was the second set that was the major test for Murray.
The three-time Grand Slam winner consistently earned break points on Norrie's serve, but it was the 24-year-old who initially got his nose in front, breaking for 4-2 with a fine forehand winner.
In response, after saving set point at 5-3 down, Murray finally took a break-point opportunity at the eighth time of asking and held to get back on level terms.
After some lengthy exchanges in the second, though, Murray was struggling and, at times, looked physically spent:
Norrie dominated the second-set tiebreak and levelled the match with a fine forehand pass, and he looked to be in the ascendancy with Murray struggling.
However, the two-time Wimbledon champion then provided a glimpse of his former best as he came out in the third and blitzed his opponent.
A near-perfect opening service game, which included an ace and an inside-out forehand winner, set the tone.
Norrie failed to force Murray into long rallies that could have tired him out, feebly conceding a 2-0 lead to the 32-year-old with a double fault.
But Murray also did not allow his opponent to play well in the decider and used the drop shot to fantastic effect and showed stamina that had not been apparent in the second.
A big backhand on match point forced Norrie long, and Murray could now face top seed Dominic Thiem in the last eight.