Bulgarian Grigor Dimitrov has made his first grand slam quarter-final by defeating Argentinian Roberto Bautista Agut at the Australian Open.

The 22-year-old 22nd seed showed character beyond his years to overcome the unseeded Spaniard 6-3 3-6 6-2 6-4 in two hours and 24 minutes.

Coached by Lleyton Hewitt’s former trainer Roger Rasheed, Dimitrov recovered from 0-30 down at 4-4 in the fourth set to hold serve and set up a chance to win the match.

He took that chance with combative stroke play, breaking Bautista Agut to close out a four-set victory.

Dimitrov’s serve was a major asset, slamming 11 aces with his fastest at 219km/hr.

An elated Dimitrov was all smiles at making the last eight at Melbourne Park.

“I feel great, a bit tired, he gave me hell out here today,” he said.

“But I’m just happy.”

Best known as the boyfriend to Russian world No.3 Maria Sharapova, Dimitrov will play the winner between world No.1 Rafael Nadal and Japanese 16th seed Kei Nishikori in the quarter-finals.