Who? Sebastian Ofner is the latest Cinderella story at Wimbledon

There is no Marcus Willis at this year's Wimbledon, at least not in men's singles, but there is a Sebastian Ofner.

The 21-year-old Austrian, a qualifier ranked No. 217, is into the third round following a five-set win against Jack Sock—a run that's surprised even him.

"It's my first Grand Slam," he said. "I never played before on grass, and now I'm in the third round, so I can't believe [it] either."

It's not just grass that's new for Ofner. He barely sneaked into the qualifying event, reaching the final of a small $50,000 Challenger a few weeks before to lift his ranking from No. 270 and get into his first Grand Slam qualifying draw. Despite his lack of grass-court experience, he won three rounds in qualies, coming from two sets down in the final round to beat Jay Clarke in five sets.

Ofner then defeated Thomaz Bellucci in the first round to get his first tour-level win, and then played—and won—against his first Top 20 opponent, Sock.

"It was the first time I played against such a good guy, and I won," he said. "So [I] can't believe it now."

But though he's surprised by his performance at Wimbledon, he did see himself as competitive at the ATP level.

"Yeah, I played some Challengers before, and I saw I'm not far away from good players," said Ofner.

Improvements in his serving and forehand have also helped.

“I think what I'm doing better now is I'm focusing more on myself,” he said. “And, yeah, I was practicing very hard and a lot. I think that's why I'm here now."

The run should see him gain at least another 40 spots in the rankings, and add $160,000 to his career winnings of around $46,000.

"It's more than doubled what I earned till now in my career," he said.

Ofner took up tennis as a child and was picked up by the Austrian federation as a 14-year-old, but did not play tennis full-time until he finished school at 19 years old. According to Ofner, he was too small for success at that age.

"I was not good in juniors," he said.

He now trains at Gunter Bresnik’s academy, run by the coach of No. 8 Dominic Thiem. Ofner is coached by Thiem's father, Wolfgang, and is friendly with Dominic, who he has been hearing from since his first-round win in qualifying.

"He said congratulations,” Ofner said, “and he was also very happy that I qualified, and then that I won against Bellucci. And now for sure he's also very happy that I won against Sock.”

Ofner now plays 20-year-old Alexander Zverev, who is also friendly with Thiem, and he joked that he would be asking his fellow Austrian for strategy and advice.

It's still all new for him, but he's finding his way around.

—GRAND SLAM WEEK: WatchWimbledon Primetime on Tennis Channel, and catch up on the other 2017 Grand Slams on Tennis Channel Plus

—Watch encores from the 2017 French Open and Australian Open on Tennis Channel Plus, including matches like the AO Final showdown between Serena & Venus Williams**