Fourth-seeded Alexander Zverev served 29 aces in a late-finishing 7-6 (5), 6-4, 5-7, 6-7 (6), 6-1 win over Jeremy Chardy to reach the third round of the Australian Open.
The ATP Finals winner had control in the first two sets before the No. 36-ranked Chardy rebounded to level at two sets apiece and force the second-round match into a fifth set.
They finished after midnight, delaying the later night match on Margaret Court Arena between Johanna Konta and Garbine Muguruza.
"What an amazing match. Jeremy fought so hard," Zverev said. "He's an unbelievable player. He's a great fighter."
Novak Djokovic was also victorious, sweeping Jo-Wilfried Tsonga 6-3, 7-5, 6-4 on Thursday.
Eleven years ago, Djokovic's victory over Tsonga gave the Serb the first of his 14 Grand Slam titles, a total that is tied for third most for a man.
"Certainly you could feel tension on the court from the beginning. I think we were both going through a lot of emotions," Djokovic said during an on-court interview.
Asked to elaborate on that sentiment at his news conference, Djokovic said: "Knowing the history ... I had with him, I guess that's what brought even more ... weight on this encounter tonight. I did feel a bit more nervy than I usually do."
Tsonga needed a wild-card entry to get into this year's field because his ranking is only 177th. He missed most of last season after having surgery on his left knee in April.
"It's always tough playing with Jo," Djokovic said. "Ranking doesn't do justice to him at the moment. He's always been a top player."
Djokovic now faces 25th-seeded Denis Shapovalov, a 19-year-old Canadian who beat Taro Daniel 6-3, 7-6 (2), 6-3.
Shapovalov, who described facing Djokovic at a major tournament as "a dream come true to me," is one of 10 men under age 23 into the third round, the most at the Australian Open since there were 11 in 2004.
Milos Raonic kept holding off Stan Wawrinka, denying him opportunities to take the second, third and fourth sets en route to a 6-7 (4), 7-6 (6), 7-6 (11), 7-6 (5) victory that put the 16th-seeded Canadian into the third round at Melbourne Park for the eighth time in nine appearances.
Already up a set, Wawrinka was only two points away from taking the second set but couldn't do it. About an hour later, Wawrinka, the 2014 Australian Open champion, was a single point from grabbing the third set and was denied again. Another hour after that, Wawrinka was two points from seizing the fourth to force a fifth but came up short.
Wawrinka kept coming oh-so-close, and Raonic kept hanging in there and toughing out the most important moments.
"It feels like four hours passed by in about 15 minutes. ... The adrenaline takes over," said Raonic, the runner-up at Wimbledon in 2016. "I was very fortunate to stay alive in that fourth set."
The match was interrupted for about a half-hour while the roof at Rod Laver Arena was shut because of rain at 4-all in the third set. Raonic thought that helped him quite a bit.
"I do a little bit better indoors than outdoors," he said, "so thank you for raining up there."
Raonic had 39 aces, part of an impressive ratio of 84 total winners to only 44 unforced errors.
This was a matchup probably better suited to the second week than the second round of a Grand Slam tournament, given both men's credentials. But Wawrinka, a three-time major champion once ranked as high as No. 3, dropped out of the top 250 last season when he had surgery on his left knee.
His signature one-handed backhand is as dangerous as ever -- with a 16-2 edge in winners on that shot Thursday -- and he hit 28 aces of his own. But as even as the match was in many respects -- Raonic won only two more points overall, 163-161 -- Wawrinka couldn't come through when he really needed to.
Raonic had plenty to do with that, including in the third-set tiebreaker, when he served his way out of trouble.
Wawrinka's three set points there came at 6-5, when Raonic delivered a serve at 129 mph followed by a forehand volley winner; at 8-7, when Raonic's 125 mph serve drew a missed return; and at 10-9, when an ace at 132 mph did the trick. A 123 mph service winner gave Raonic that set.
In the last tiebreaker, Wawrinka was up 5-4 before Raonic closed with three consecutive points to avoid heading to a fifth set.
Raonic moves on to face Pierre-Hugues Herbert, who scored a 6-2, 1-6, 6-2, 6-4 victory over South Korea's Hyeon Chung, a semifinalist last year.
In other men's action on Day 4, 2014 US Open runner-up Kei Nishikori withstood 59 aces from Ivo Karlovic to win 6-3, 7-6 (6), 5-7, 5-7, 7-6 (7).
"That's almost my one-year aces [total]," Nishikori joked. "Never easy. Kind of frustrating if you can't get the serve like three in a row."
The 6-foot-11 Karlovic -- who holds the Australian Open record of 75 aces in a match -- got to six aces in a row at the end of the fourth set.
Still, the No. 8-seeded Nishikori moved on, as did No. 11 Borna Coric and No. 12 Fabio Fognini.
The Associated Press contributed to this report.