Andy Murray squeezed past John Isner at the Shanghai Masters on Thursday as Jo-Wilfried Tsonga was also pushed all the way before ending the fairytale run of Spanish qualifier Albert Ramos-Vinolas.
Murray lost the first set tiebreaker and snapped at the umpire as his frustrations rose in the second set – before he finally broke the big-serving Isner and levelled the match at a set each.
The world No.2 broke again for 4-3 in the decider and he left the top-ranked American on his backside as he fended off break points in his next service game, before going on to take it 6-7 (4-7) 6-4 6-4.
“Obviously, it’s tough to maintain your patience and not get a bit frustrated when you do get the chances and, you know, he serves an ace,” Murray said.
“There were like 13 break points. I would imagine he served an ace on at least half of those. He served very well when he was behind.”
The two-and-a-half-hour workout puts the Briton into a quarter-final against Gilles Simon of France or Czech Tomas Berdych as he seeks his third title in Shanghai.
The 70th-ranked Ramos-Vinolas came through qualifying before stunning defending champion Roger Federer in the second round for the biggest win of his career – but Tsonga proved a match too far.
However, the 27-year-old Spaniard gave the mercurial Frenchman a massive scare when he took the first set before going down fighting 6-7 (5-7) 7-5 6-4 in two hours and 45 minutes.
Top seed and world No.1 Novak Djokovic had an easier time, beating Spanish 15th seed Feliciano Lopez 6-2 6-3.