British wildcard Ryan Peniston marked his ATP Tour main draw debut with a stunning win over French Open finalist Casper Ruud at Queen's.

Peniston sealed victory when Ruud hit a first serve return into the net, sparking jubilant celebrations between him and the home support in London.

"I can't really believe it, it feels like a dream," he said.

"I didn't get much sleep last night thinking about this match. It doesn't feel real."

Left-hander Peniston meets Argentina's Francisco Cerundolo or Spain's Pedro Martinez in the second round.

The biggest win of his career came on the same day he was given a wildcard for Wimbledon, which starts on 27 June.

Ruud, 23, reached a career-high ranking of five after his run to the Roland Garros final, where he lost to Spain's Rafael Nadal.

Grass is not the Norwegian's favoured surface, and he once joked it was for playing golf and not tennis.

Peniston, who spent four years learning his craft at the University of Memphis between 2014 and 2018 before turning professional, is more adept on the grass courts and it showed as he refused to let Ruud settle.

In the run-up to Queen's, Peniston reached the quarter-finals at Challenger events in Surbiton and Nottingham.

The British number seven looked relatively comfortable on serve in the first set, not facing a break point until the 12th game when he was helped by a slip by Ruud.

Ruud needed treatment on his upper leg at the end of the set but did not look too impaired when he returned to court.

Another tight set saw the pair exchange breaks of serve midway through, before Peniston dominated the tie-break to claim the biggest win of his career.

"I've been playing well - obviously Casper is an unreal player and did so well in French Open, so I knew it was a tough ask," he said.

"But you have to step on the court thinking you have a chance to win and that's what I did. That's all I could do.

"It's a bit surreal because four or five years ago I was sat over there watching this tournament."