Sebastian Baez stunned world number 18 Cristian Garin in three sets to reach the last eight at the Cordoba Open, his first career ATP Tour quarter-final.

Baez took a set off Stefanos Tsitsipas – his first ever top-10 opponent – before losing at the Australian Open, but he has kicked on again in Argentina.

The 21-year-old faced a huge uphill battle when he fell a set behind to third seed Garin, who won in Cordoba in 2020.

However, Baez roared back in quite remarkable fashion to prevail 4-6 6-1 6-1 in perhaps the best result of his career – and one of his opponent's worst.

"It was a pretty bad match, one of the worst of my career in terms of feeling," Garin said. "He deserves it as well, but I feel like I wasn't up to it.

"I had a regular first set and then I couldn't find myself. The little adaptation I had was clear, I was slow. It was one of my worst matches in many years."

Baez faces Alejandro Tabilo next after his last-16 defeat of Carlos Taberner, but a tricky field remains as the two seeds in action besides Garin on Thursday both won.

The reward for Lorenzo Sonego and Albert Ramos-Vinolas is a match against one another on Friday.