World number 172 Thiago Seyboth Wild beat the second seed Daniil Medvedev in five sets on Tuesday to reach the second round at a Grand Slam tournament for the first time.
The 23-year-old Brazilian qualifier won 7-6, 6-7, 2-6, 6-3, 6-4 in four hours and 15 minutes on centre court.
Seyboth Wild had two set points in the second set but fluffed them both to allow his more illustrious opponent back into the match.
And the setback appeared to perturb him at the start of the third as he dropped his service. Though he recovered the break to level at 2-2, Medvedev won four consecutive games to take the third 6-2.
But the 27-year-old Russian was off the pace. His shots failed to ruffle an opponent who was spraying winners with abandon.
Cost
Medvedev's sloppiness cost him in the fourth set. Trailing 2-3 with a game point, he queried a call which the umpire refused to overrule.
Soon it was 4-2 to Seyboth Wild and he held on to take the match into the decider against one of the tournament favourites.
Medvedev, who won the Masters tournament in Rome nine days ago, botched his opening service game of the decider.
From 40-0 up he lost four consecutive points and though he saved the first break point with a backhand winner, he fluffed a volley on the second to give Seyboth Wild the early boost. He held for 2-0 with some more big hitting.
With two points for a 3-1 lead, errors crept into the Brazilian's game and Medvedev clawed his way back to level for 2-2.
But he immediately squandered the chance to take the lead. However, Seyboth Wild was in an equally munificent mood and it was 3-3.
Medvedev lost his serve again to trail and the Brazilian held for 5-3.
The only question remaining: would the inexperience comes to the fore? A forehand winner brought up match point and, fittingly, another forehand special down the line furnished him with the most spectacular win of his career.
"I've watched Daniil playing throughout my junior career," said Seyboth Wild. "I've dreamed of playing against these kinds of player on this kind of court ... I've been living out my dream and to win is a dream come true."
Elsewhere in the lower half of the men's draw, the fourth seed Casper Ruud disposed of Elias Ymer from Sweden in staight sets.
Return
Last year's beaten finalist won 6-4, 6-3, 6-2. "It was nice to be back," said the Norwegian.
"There were some nerves as well obviously. Being back the first round is always a little tension but I came through in straight sets just what you want to start with. And I felt better and better towards the end of the match."
It was emotional return for Alex Zverev. The German twisted his abkle during the semi final last year against Rafael Nadal and was out for six months reco vering.
He moved past the South African Lloyd Harris 7-6, 7-6, 6-1.
In the early matches in the women's draw, last year's runner-up Coco Gauff advanced to the second round with a three-set win over Rebeka Masarova from Spain. It finished 3-6, 6-1, 6-2 to the 19-year-old American.
"I was happy that I could turn it around," said Gauff. "Getting to last year's final is in the past. I just told myself that I could turn it around and it helps that I'm confident on this surface and in these conditions."
Seventh seed Ons Jabeur saw off Lucia Bronzetti in straight sets and there was joy for the partisans as Diane Parry toppled the 25th seed Anhelina Kalinina from Ukraine.
