Top-seeded Novak Djokovic fended off a spirited challenge from Frances Tiafoe in the second round of the Australian Open, beating the young 23-year-old American 6-3, 6-7 (3), 7-6 (2), 6-3 in a 3½-hour match.
Tiafoe, who reached the quarterfinals here two years ago, threw everything he could at the eight-time Australian Open champion in the afternoon match on Rod Laver Arena.
"He pushed me to the very limit," Djokovic said. "I was trying to work around his backhand and kind of penetrate through the court there, open him up, but he wasn't giving me anything.
"He's a very quick player. It's unpredictable what comes next ... I'm really glad to overcome such a battle."
Both players were on serve in the fourth set and looked headed for another tiebreaker when Tiafoe was given a time violation on his serve. He lost his temper -- and then his serve -- to fall behind 3-4. He didn't win another game in the match, which finished with a double fault.
"Those kinds of things are just unlucky," Djokovic said. "He deserved to have the first serve."
Tiafoe later said he was glad Djokovic acknowledged it, but he still thinks there needs to be "conversations" about allowing more time between points while COVID-19 pandemic restrictions mean ball kids can't hold the towels for players.
"Could I have handled it better? Yes," Tiafoe said, answering his own question. "Yeah, I mean, that just broke me. I'm out there battling world No. 1, and like he needs any more help, you know."
Though Tiafoe played an aggressive match, Djokovic was better when it mattered. He had the edge in terms of winners (56-49), aces (26-23) and converted five break points to just two for Tiafoe.
"Credit to him for forcing me to feel uncomfortable," Djokovic said.
After taking a quick look at the stats, Djokovic said he couldn't remember serving more aces, or seeing more serves pass him, in a match in a long time. He'll next play No. 27-seeded Taylor Fritz, who held off Reilly Opelka 4-6, 7-6 (6), 6-7 (4), 7-6 (5), 6-2.
Djokovic had lost in the second round only once at Melbourne Park, against Denis Istomin in 2017.
In other men's matches, US Open champion Dominic Thiem eased through the second round with a 6-4, 6-0, 6-2 win over Dominik Koepfer.
The No. 3-ranked Thiem reached his maiden Grand Slam final in Australia last year before losing to Djokovic. He went one better at the US Open by claiming his first major trophy.
He next will face Australian Nick Kyrgios, who saved two match points in the fourth set before beating 29th-seeded Ugo Humbert 5-7, 6-4, 3-6, 7-6 (2), 6-4 in a momentum-swinging second-round match.
Kyrgios, frustrated with a number of let calls throughout the first two sets of his match, threatened to stop playing if chair umpire Marijana Veljovic didn't turn off the automatic net cord.
"Turn it off. [Umbert's] serve missed by that much," Kyrgios said to Veljovic while gesturing a six-inch gap, following a game in which his opponent was called for a dubious let. "It's ruining the game do you understand it? You don't understand it. It's ruining the game. How do you understand it?"
Kyrgios is playing in his first major since the 2020 Australian Open. He hasn't left Australia since the COVID-19 pandemic began.
Former Australian Open champion Stan Wawrinka wasted a big lead in the fifth-set tiebreak -- and three match points -- before losing to Marton Fucsovics 7-5, 6-1, 4-6, 2-6, 7-6 (11-9).
Wawrinka had won four of his eight previous five-setters at the Australian Open, and he nearly made it another. But five unforced errors in the last seven points of the tiebreaker cost him the match. The three-time major winner had 73 unforced errors in total, including 43 on his normally reliable one-handed backhand.
No. 8 seed Diego Schwartzman took care of Alexandre Muller 6-2, 6-0, 6-3. Denis Shapovalov, the No. 11 seed from Canada, cruised past Australia's Bernard Tomic 6-1, 6-3, 6-2, advancing along with two other Canadians, Milos Raonic and Felix Auger-Aliassime.
The Associated Press contributed to this report.