WIMBLEDON, England — It was Lukas Rosol and not Rafael Nadal who looked like a two-time Wimbledon champion used to pummeling opponents into submission on tennis’ biggest stage.

It was Rosol, and not Nadal, who sprinted to and from his chair during changeovers like he had a never-ending supply of energy, pumped his fist and shouted to his entourage in the player’s box. And it was the 100th-ranked, little-known Czech player making his first Wimbledon appearance — and not the 11-time Grand Slam winner — who got better and stronger as the second-round match on Centre Court progressed into the night.

He hit ace after ace to complete one of the biggest upsets tennis has seen in years.

As surprising as Rosol’s five-set victory over Nadal was, the manner in which he completed it Thursday was perhaps equally stunning.

“In the fifth set he played more than unbelievable,” Nadal said.

He wasn’t the only one who struggled to believe what they were seeing.

Rosol, who had lost in qualifying for Wimbledon in each of the last five years, simply outclassed Nadal with his powerful serving and booming ground strokes. He hit cross-court backhand winners that measured 99 mph, he stepped up to whip scorching forehand returns, and he served so well that Nadal hardly tried to get to them by the final game. The last one he hit was his 22nd, and it wrapped up a 6-7 (9), 6-4, 6-4, 2-6, 6-4 victory that no one had seen coming.

Least of all Rosol himself.

“I’m not just surprised; it’s like a miracle for me,” he said.