Roberto Bautista Agut came through a third Australian Open five-setter on Sunday to knock out 2018 finalist and sixth seed Marin Cilic in the fourth round. The in-form Spanish 22nd seed will play in his first Grand Slam quarterfinal after winning 6-7 (6/8), 6-3, 6-2, 4-6, 6-4 in two minutes under four hours on Margaret Court Arena. Bautista Agut began his season by beating Novak Djokovic en route to the Doha title and now faces Stefanos Tsitsipas for a place in the semifinals after the young Greek star upset defending champion Roger Federer.
"I've been playing very good tennis," Bautista Agut told reporters.
"I won really good matches. I had to fight so hard to stay very focussed.
"It's been a great month for me and for my tennis."
He began his Australian Open campaign with an epic five-set win over Andy Murray, in what could be the three-time Grand Slam winner's last match because of a chronic hip injury.
His second round match against Australian John Millman also went the full distance before a straight-sets third round win against 10th-seeded Russian Karen Khachanov.
On Sunday he ended Croat Cilic's hopes of a repeat match-up against Federer in the quarterfinals after losing to the Swiss master in five sets in last year's final.
At the Rod Laver Arena, young Stefanos Tsitsipas signalled a changing of the guard at the top of world tennis as he shocked defending champion Roger Federer.
The NextGen Finals champion beat Federer, who is 17 years his senior, 6-7 (11-13), 7-6 (7/3), 7-5, 7-6 (7/5).
Tsitsipas, seeded 14, became the first Greek in history to reach the quarterfinals of a Slam.