Seventeen-year-old Carlos Alcaraz reached his first main tour quarter-final on Thursday with a three-set victory over 39-year-old Spanish compatriot Feliciano Lopez at the Andalucia Open.
World number 133 Alcaraz won 4-6, 6-2, 6-4 over the sixth-seeded Lopez, ranked 64 but who once reached 12 in the rankings.
The second round match featured the biggest age difference between two players since Vienna in 2011 when Dominic Thiem, then 18, defeated 44-year-old Thomas Muster
When Lopez turned pro in 1997, it would be another six years before Alcaraz was born.
"It was a difficult match, Feli is a great player with a great serve and great volley," Alcaraz told atptour.com.
"I started the match very well with a break in the first few games, but I got a little bit lost toward the end of the first set. Feli took advantage of that, and of course he used his experience in those moments.
"The key was that I stayed calm after losing the first set. I came out in the second set very focussed and knowing what I had to improve."
Alcaraz will next face third seed Casper Ruud after the Norwegian eased to a 6-3, 6-2 victory over Gianluca Mager of Italy.
Spain's Jaume Munar, ranked 95, also claimed his first top 20 victory of the year with a 6-2, 6-1 win against second-seeded Fabio Fognini.
Munar will take on Ilya Ivashka in the quarter-finals, after the Belarusian defeated fifth seed Alejandro Davidovich Fokina, 6-1, 6-3.