Groth booked a spot in his first ATP semi-final at the Hall of Fame Championships at Rhode Island with a stunning 6-3 6-4 win over defending champion and fourth seed Nicolas Mahut.

He sent down 10 aces and saved the only break point he faced to oust the Frenchman in 77 minutes.

“I’ve had a great grasscourt season already,” the world No. 123 said.

“I had nothing to lose.

“I went out there confident and I thought I played really well.”

Groth booked a semi-final date against Croatian second seed Ivo Karlovic, who ousted Israel’s Dudi Sela 7-6 (7-3) 7-5 at the $512,000 event.

With his three wins this week, Groth will jump into the top-100 and book a spot in the US Open main draw.

“I’ve got myself in great shape,” Groth said.

“I’m not losing my mind out on court.

“I’m doing a lot of things better and I’ve tightened up my groundstrokes.

“I’m volleying better than I ever have.

“I’m making it tough for guys to break me.

“I’m becoming more prepared to be a top player.”

Groth has matched his ATP match triumphs from the past 18 months in less than a week.

His only two prior singles wins this year came at Brisbane in January, while he had one win in Washington last year.

Karlovic, who blasted nine aces to dispatch Sela in 92 minutes, beat Groth 7-6 (7-4) 6-3 in a first-round match at Delray Beach earlier this year.

Groth made the semi-finals of the French Open doubles and achieved a lifelong ambition by qualifying for Wimbledon.