Matteo Berrettini was made to work for victory over South African Lloyd Harris at Indian Wells on Tuesday, eventually prevailing 6-4, 7-5.
The Italian, 25, admitted afterwards he would need to work harder in the next round.
“I got a little bit nervous,” he said.
“I didn’t like how I handled the start of the second set. I let the anger out a little bit, which helped. I found the right balance in order to break him in the important moment and I then had the momentum.”
Berrettini was 4-1 down ion the second set before mounting a comeback, winning five straight games to secure the victory.
In the fourth round he will face Miomir Kecmanovic, who beat Botic van de Zandschulp of the Netherlands 7-6 (7/3), 7-5.
American John Isner was too powerful for Argentina’s Diego Schwartzman, winning 7-5, 6-3.
Isner fired 13 aces in the natch and joins fellow Americans Taylor Fritz, Jenson Brooksby and Reilly Opelka in the next round.