Zverev after 2 a.m. thriller: "This is the match I needed" VIDEO

After nearly five hours of play, Zverev beat Lorenzo Sonego 6-4, 3-6, 6-7, 7-5, 6-4 at around 2 a.m.

The German was on the brink of elimination — with Sonego leading 5-4 in the fourth set, Zverev was serving and the Italian was just two points away from victory.

But the world No. 2 somehow found a way out of an almost lost situation.

"I’m just happy I won. That’s it," a visibly relieved Zverev said after the match.

Zverev was playing as the top seed at a Grand Slam for the first time, but his start did not live up to that status. The German was particularly troubled by uncharacteristic forehand errors.

"An incredible battle. There were so many ups and downs. Nearly five hours in the first round... I think this is the longest first-round match I’ve ever played in my life. Credit to him, he played incredible tennis. I’m sure he would have beaten a lot of players today, but I’m happy to have made it through."

In fact, this was the second-longest match of Zverev’s career, lasting four hours and 53 minutes, behind his clash with Carlos Alcaraz at last January’s Australian Open, which lasted five hours and 27 minutes.

After it was all over, the German admitted that this was exactly the kind of match he needed.

"This is exactly the kind of match I needed. I struggled at the last two tournaments," Zverev said, referring to his results in Montreal and Cincinnati, where he went 2-2.

"Sometimes good things happen after you fight your way through matches like this. Hopefully, that will be the case at this tournament too."

Zverev will now face Frenchman Quentin Halys in the second round.

The German leads their head-to-head record 2-0, with both meetings coming this year — in Miami and at Roland Garros.

Zverev has recorded 47 ATP Tour wins this season, the most of any player, including 19 victories at Grand Slam tournaments.