Cameron Norrie battled past Tomas Machac in three sets to reach the third round of the Madrid Open, but fellow British hopeful Katie Boulter was beaten by fifth seed Jessica Pegula on Friday.
Norrie comfortably claimed the opening set of his encounter with Machac, but then spurned a match point in the second as his Czech oponent took him to a decider.
Norrie was then staring at defeat, a break down trailing 5-3, but the British No 1 crucially broke when Machac was serving for the match and he'd this time take the tiebreaker.
The 30-year-old prevailed 6-2 6-7 (6-8) 7-6 (7-5), describing his victory as "one of the favourite matches" of his career.
"I was feeling the ball really well in the first set but it was tough to hang with him in the second and I had to dig deep in the third set when I was down a break," Norrie told Your Site.
"It was so, so good. It was one of the favourite matches of my career - the atmosphere was so good and it tested me in so many ways.
"These are the kind of matches where you can get through them and go on to have a great week."
Norrie will play either Thiago Agustin Tirante next, after the Argentine dumped out 15th-seeded American Tommy Paul.
Norrie, who reached the quarter-finals of the Barcelona Open last week, has never before made it past the third round in the Madrid.
Boulter was unable to join Norrie in the third round, the 29-year-old losing out 6-4 6-4 to fifth seed Pegula.
Boulter followed fiance Alex De Minaur on court following his chastening loss to Spanish youngster Rafael Jodar and, although she put up a decent fight, it was double defeat for the couple.
Elsewhere, world No 1 Jannik Sinner came from a set down to beat France's Benjamin Bonzi 6-7 (6-8) 6-1 6-4 for his 18th successive victory after lifting titles at Indian Wells, the Miami Open and Monte Carlo Masters.
Australian Open champion Elena Rybakina overcame a difficult start to beat Romania's Elena Gabriela Ruse 4-6 6-3 7-5, while Coco Gauff secured an emphatic 6-3 6-0 victory over Leolia Jeanjean to reach the third round.
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