Sat in his chair before a ball had been hit, before his opponent Ricardas Berankis had arrived on Court 17, Marcus Willis pumped his fist for the crowd.

As well he might. This may have been the opening day of The Championships, but the world No.772’s improbable Wimbledon campaign is into its third week and, incredibly, the second round.

Willis, born in Slough, based in Warwick, and contemplating a coaching career, beat Lithuania’s world No.54 Berankis 6-3, 6-3, 6-4. The 25-year-old had never played a tour-level match before; his second will be against Roger Federer.

“I'm not sure he can play on grass – that's good,” joked Willis. “It's an amazing dream come true. I get to play on a stadium court. This is what I dreamed of when I was younger.

“I'm going to go out there and try to win the tennis match. I probably won't. I might not. But I'm going to give everything, as I have the last seven matches.”

And to think, this might never have happened. Willis was a late addition to the British pre-qualifying tournament, handed a spot when Scott Clayton could not get back from Turkey in time. 

Moment of victory for world No.775 Marcus Willis

The 25-year-old earned himself a wild card into qualifying, where he sliced and diced his way past Yuichi Sugita, Andrey Rublev and Daniil Medvedev, delivering on the promise so many had seen in him as a junior.

“When I was a junior, yeah, I was talented,” Willis said. “I was bigged up a lot. Then I got dropped in the real world. Played a few years in Romania, losing. I lost a lot of confidence, made some bad decisions, went out too much, lifestyle wasn't good. Yeah, I didn't have the drive.

“I found it three years ago. I worked very hard with my coach Matt Smith in Surbiton – ridiculous times in the morning, ran myself into the ground. But it's worth it now.”

Marcus Willis fans go wild after stunning first round win

Prior to that, however, Willis had planned to walk away from competitive tennis.

With just $64 to show from his individual exploits in 2016, injuries and dwindling funds had forced him to take a coaching role at Warwick Boat Club and prompted searches for posts in the United States.

But girlfriend Jenny Bate talked him into one last shot at the tour. It may prove to be the most important conversation of his life.

Willis is guaranteed £50,000 for reaching the second round, more than half his career earnings to date – and it was well-earned. The unconventional left-hander flummoxed Berankis for three rowdy sets.

The atmosphere on Court 17 was, let’s say, unique. With supporters chanting ‘Shoes off if you love Willis’ with their trainers held aloft, Willis vamped to the crowd, boogied between games, said ‘too good’ when Berankis hit a winner, and kept racking up games.

“I put a shoe in the air, as well,” Willis admitted with the widest smile in south-west London. “Joined along with it – keeps me relaxed, to be honest.” 

In all the Lithuanian had 20 break points, including eight in the third set; he converted just one, while already trailing in the second set. Willis gave himself a lead to defend, and defended it with everything he had. “I'm sure on another day he'll chop me up,” he admitted.

It wasn’t always pretty, but there were moments of brilliance from Willis as he showed fine touch at the net, frustrated Berankis with interminal slice forehands and thumped the occasional passing winner that brought the crowd to their feet.

The dancing continued long after the Lithuanian framed his return wide on match point. Willis hugged his cheer squad, his family, his girlfriend, lapping up his moment in the Wimbledon sun.

“I've always wanted to play at Wimbledon,” Willis said. “I just never thought it would happen. Two, three, four years ago, it was looking very unlikely. Now I'm here. I'm going to enjoy every minute and try and do it on a regular basis.”