After 13 years on the ATP Tour, and 16 years removed from a serious car crash that nearly ended his career, Denis Istomin enjoyed the best moment of his career Thursday.

The 30-year-old Uzbekistani recorded one of the biggest upsets in Australian Open history, beating six-time champion Novak Djokovic 7-6 (8), 5-7, 2-6, 7-6 (5), 6-4 in a second-round match in Melbourne, Australia.

Istomin, ranked 117th in the world, has only twice reached the fourth round in a Grand Slam event, and he has never advanced further. Djokovic, a 29-year-old Serbian seeded second this fortnight, has 12 major titles to his name.

“I feel sorry for Novak. I was playing so good today,” Istomin said on court after the victory. “I surprised myself today.

“It was hard. Since the third set, I got cramping in my legs, but I still felt normal.”

Istomin earned the only service break of the final set to take a 3-2 lead, then closed out the 4-hour, 48-minute match while exhibiting little of the nerves that might be expected from a mid-level player chasing his greatest accomplishment.

“It is biggest win for me,” Istomin said. “It means so much. Now I feel I can play with these guys and be on this level.”

Before Thursday, Istomin was best known for coming back from a car wreck that caused leg fractures and kept him out of tennis for two years.

The early-round upset loss was the second for Djokovic in less than a year. He fell to then-41st-ranked Sam Querrey in the third round at Wimbledon last summer, the first time he had failed to reach the quarterfinals of a Grand Slam event since the 2009 French Open.

Prior to the Istomin-Djokovic match, the Thursday men’s singles action wasn’t exactly gripping.

Each of the first seven seeded men to play sailed to a second-round victory, and only two were forced to a fourth set.

Third-seeded Canadian Milos Raonic beat Luxembourg’s Gilles Muller 6-3, 6-4, 7-6 (4).

Fifteenth-seeded Grigor Dimitrov of Bulgaria got past South Korea’s Hyeon Chung 1-6, 6-4, 6-4, 6-4, while 21st-seeded David Ferrer of Spain topped American Ernesto Escobedo 2-6, 6-4, 6-4, 6-2.

Dimitrov said, “That first set, he definitely played lights-out. I had to be respectful of that, and I was. But as soon as the second set started, I felt confident. And that’s nice to feel.”

Dimitrov is hoping to advance to the quarterfinals of a major tournament for the third time in his career. He reached the quarters in Australia in 2014, then got to the semifinals at Wimbledon that summer.

Dimitrov captured the championship of the Australian Open warm-up event at Brisbane earlier this month, the fifth singles title of his career.

“Definitely I had been struggling to win a tournament,” Dimitrov said. “That really took an emotional toll. But at the start of the year, we set the goal to win a title in the first six months. I’ve done that already.”

Escobedo, a 20-year-old Los Angeles native, was appearing in just his second Grand Slam event. He fell in the second round of the U.S. Open last year.

Thirteenth-seeded Roberto Bautista Agut of Spain wiped out Japan’s Yoshihito Nishioka 6-2, 6-3, 6-3. Another Spaniard, 30th-seeded Pablo Carreno Busta, took care of Great Britain’s Kyle Edmund 6-2, 6-4, 6-2.

France’s Richard Gasquet, the No. 18 seed, barely broke a sweat in a 6-1, 6-1, 6-1 rout of Argentina’s Carlos Berlocq. No. 25 Gilles Simon, another Frenchman, routed Brazil’s Rogerio Dutra Silva 6-4, 6-1, 6-1.

Germany’s Philipp Kohlschreiber, the 32nd seed, got better as he went along in a 7-5, 6-3, 6-0 victory over American Donald Young.