The 27-year-old won a rollercoaster five-setter to end the Australian Open campaign of teenage countryman Thanasi Kokkinakis and qualify for the third round of a grand slam for the first time.

Owner of the world’s fastest serve, Groth crunched 26 aces to chisel out a memorable 3-6 6-3 7-5 3-6 6-1 victory over one of Australian tennis’ next big things.

His cash reward was a guaranteed $97,500, with more on the line if he is able to make it into the fourth round.

His third round opponent will be fellow Australian Bernard Tomic, who last night defeated German 22nd seed Philipp Kohlschreiber 6-7 6-4 7-6 7-6.

“I feel like I’m in career best form and I’m where I’m at in the rankings for a reason,” Groth, the world No. 82 who only broke into the top 100 for the first time last year, said.

“I’ll come back firing on Friday. I have the opportunity to play in the second week.

“So if I can win another match and get in the second week, I feel like I deserve to be there.”

Despite his confidence, Groth conceded he was still pinching himself at being in the last 32 of a major.

“It’s a fair way from the grass courts of Corowa and Albury,” he said.

“I’m a country boy. I always wanted to play on the big courts. That was my dream. Now I’m living that dream.”

Kokkinakis was valiant in defeat.

After upsetting world No. 13 Ernests Gulbis in his first five-set match on Monday night, Kokkinakis again threatened to pull off a mighty comeback victory.

But the 18-year-old 

appeared to twinge a hamstring early in the deciding set as the higher-ranked and more-experienced Groth raced to a 5-0 lead before advancing to round three after two hours and 53 minutes.