Melbourne, Jan 20 (IANS): Roberto Bautista Agut stormed into his maiden Grand Slam quarterfinal on Sunday after beating Croatia's Marin Cilic in a five-set battle at the ongoing Australian Open.

The Spaniard, seeded 22, routed his Croatian opponent, the sixth seeded Cilic, 6-7 ( 6), 6-3, 6-2, 4-6 and 6-4 in a match that lasted for a tense four hours, reports Efe.

After he sealed his win over Cilic, and amid a roar of "Vamos", the Spaniard flexed his arms and pointed skyward remembering his late mother, Ester, who passed away last May.

"It took me a lot of work, a lot of dedication, a lot of patience," Bautista Agut said after the match.

"I had to work a lot to be in the quarterfinals this year. I played a lot of hours, I played three matches in five sets, so I'm really happy," he added.

The Spaniard was not bothered about his upcoming showdown for a spot in the semi-finals.

"Now I want to enjoy the victory and I want to recover well," he said.

"Every match here is a marathon for me, so I want to rest well and stay focused for the next match."

Bautista, who ousted an injured Andy Murray in the first round, will now go up against the winner of the match between third seed Roger Federer and 14th seed Stefanos Tsitsipas.