Although Seyboth Wild won two Challenger (second-tier) titles on clay this season, world number two Medvedev was coming into the Grand Slam tournament on the back of a title in Rome, having shown tremendous progress on the slowest surface.

It counted for nothing on a windswept court Philippe Chatrier, where the Russian seemed increasingly frustrated, arguing with the umpire and the fickle Paris crowd over a line call in the fourth set.

Seyboth Wild just had too much pace and power for Medvedev, who never found his range and capitulated after four hours and 15 minutes.

"I watched Daniil play since I was junior and beating him on such a court is a dream come true,' the world number 172 said.

"I tried to use my forehand against his and it worked pretty well. I started cramping at the start of the second set but I used my mental strength to play my best tennis."

Medvedev stole his opponent's serve early in the first set but was broken to love in the fourth game as Seyboth Wild forced a tiebreak, in which he had the upper hand.

Clearing dust off his eyes, he served for the set at 6-5 and Medvedev netted the return.

Seyboth Wild maintained the pressure on the Russian in the second set, mixing his powerful game with timely drop shots as the red dirt continued to swirl around the court.

Medvedev saved two set points in the second tiebreak and on the Russian's first set point, Seyboth Wild, with an open court for a routine overhead, sent the ball wide.

The Brazilian's game - and body - was falling to pieces as he lost the third set and requested medical assistance for a nose bleed and finger problem.

But he picked his body and game up in the fourth, levelling the contest when Medvedev's backhand sailed long.

The Brazilian kept his momentum going, opening a 2-0 lead in the decider and, although Medvedev clawed back to level at 3-3, Seyboth Wild broke again for 4-3.

He held on to his advantage and ended Medvedev's ordeal on the first match point with a booming forehand winner down the line.