Taylor Fritz battled into Monday morning before finally getting past Czech Jiri Lehecka with a 7-6 (7/4), 6-7 (5/7), 7-6 (7/5) victory in three hours to reach the quarterfinals of the ATP Toronto Masters.
The US second seed finished off a complete matched set of Masters 1000 quarterfinals as the last piece of the puzzle fell into place in Canada.
The late-night marathon lasted 39 games without a break of serve, with 15 aggregate break points going begging.
Fritz delivered two aces in the final-set tiebreaker on his way to the narrow win, moving into the last eight as Lehecka drove long.
"Making all the Masters quarters is really cool," Fritz said. "It shows consistency.
"Today I had to accept that parts of my game were just not there. I was bailed out by a lot of first serves, but I was making too many mistakes."
Fellow American Ben Shelton earned a second chance after Flavio Cobillo failed to serve out their match, with the fourth seed finally securing a somewhat contentious 6-4, 4-6, 7-6 (7/1) win.
The pair had words after the match, which Shelton characterised as nothing serious.
"(In the tiebreaker) he made a gesture (he said) it was not directed at me so we are cool," Shelton said.
The winner, who now plays Alex de Minaur, earned his 100th ATP-level win after nearly two and a half hours, firing an ace on his second match point to wrap up a place in the last eight for a third straight tournament after Wimbledon and Washington.
"It was a difficult match, I was down and out a break in the third set. But I gave myself a second chance. It was an absolute war – not an easy one," Shelton said.
"I was not hitting my spots on serve that well. I would do things differently. But coming through at the end speaks to my mental toughness and being scrappy."
De Minaur pushed his ATP winning streak to seven matches as he fended off Frances Tiafoe 6-2, 4-6, 6-4,.
The Australian won the Washington title on Sunday before plunging into the chaotic schedule at Toronto, where play began on the weekend and will continue through Thursday.
De Minaur added his voice to the growing chorus of player complaints about the new 12-day Masters calendar, which will see play start in Cincinnati this week before Canada completes its unorthodox Thursday night final.
'PROUD OF THE EFFORT'
The Australian said he wasn't helped by a third-round walkover – which gave him three straight days off in the middle of the tournament.
"I didn't enjoy having so much time. The body is used to going and going (during tournaments)," he said after ousting Tiafoe in just under two and a half hours.
"It was almost like it switched off, I had to focus to switch it back on. I had to tell myself I was still playing a tournament – still competing.
"I'm proud of the effort today."
De Minaur has now beaten Tiafoe in three of four meetings. He profited from nearly 50 unforced errors off the American's racquet while overcoming a serving slump in the second set and early into the third.
"It was never going to be easy. He has got the ability to switch it on whenever he wants. It was tricky to put him away," De Minaur said, adding that the hot, windy conditions made it even trickier.
"I was just happy to sneak away with this win," he said after booking a seventh quarterfinal of the season.
Sixth seed Andrey Rublev, runner-up last year when the tournament was held in Montreal, reached his 14th Masters quarterfinal 6-7 (3/7), 7-6 (7/2), 3-0 when Spaniard Alejandro Davidovich Fokina was forced to retire with possible cramping.
Both men ended the battle with 37 unforced errors, with sixth seed Rublev to play Fritz for a semifinal spot.