Carlos Alcaraz of Spain has beaten countryman Jaume Munar 2-6 6-2 6-1, advancing to the round of 16 of the Rio Open clay court tournament.
Alcaraz, who won his first professional title last year in Umag, also on clay, is ranked 29th.
His first professional victory in the circuit also came in Rio de Janeiro, two years ago.
“I felt like home today, it is very hard to have that so far from where I came from,” the 18-year-old said before a joyous Brazilian crowd.
In other matches, Spain’s Pablo Andujar topped Uruguay’s Pablo Cuevas 7-6 (7-2) 7-5.
Another Spaniard, Pedro Martinez, eliminated China’s Shang Juncheng 6-3 6-4.
Two top-10 players are in the field.
Italy’s Matteo Berretini, ranked No. 6, and Norway’s Casper Ruud, who moved to No. 8 after winning the Argentina Open.