Ons Jabeur marked her first match since the Wimbledon final with a comfortable victory over Madison Keys in the Mubadala Silicon Valley Classic in California on Wednesday night.
Jabuer, who fell just short of her maiden Grand Slam title last month, showed no signs of any lingering disappointment, cruising past the American world No 23 7-5, 6-1 in the second round having received a bye.
The Tunisian third seed will face either Veronika Kudermetova or Claire Liu in Friday's quarter-finals.
Jabeur got off to a strong start with an early break for a 2-0 lead before Keys surged to a 5-3 lead, but she responded by winning 10 of the next 11 games.
"I'm grateful that I played at night because it's slower and it helps me a little bit with the conditions," Jabeur, 27, said. "I knew it was going to be a tough match for me. I just tried to stay low and hit the ball as much as I can. Make her play another ball and in the end I was feeling much better."
As is becoming increasingly common at her matches, Jabeur was heavily supported inside the stadium, with fans waving Tunisia flags and wearing Tunisia football shirts in support of the world No 5.
"It feels like home seeing all the Tunisian flags and all the Tunisian people," Jabeur said in her on-court interview. "Not only Tunisians, I know there are a lot of Arabic fans here and Americans who support me, so thank you guys for coming today, I really appreciate it."
While Jabeur was emphatic in her victory, second-seeded Paula Badosa survived a scare on the way to a 6-2, 5-7, 7-6 win over qualifier Elizabeth Mandlik.
After comfortably taking the first set with two breaks of serve, Spain's Badosa went down an early break in the second against her 240th-ranked opponent, who is the daughter of four-time Grand Slam champion Hana Mandlikova.
Badosa broke back but was broken again in the 11th game to give Mandlik a chance to serve out the set and extend the match.
After breaking for a 4-3 lead in the third and deciding set, Mandlik twice had a chance to serve for the set, but they traded service breaks in the final three games to send it to the tiebreaker, in which world number four Badosa won the last five points to seal the victory.
Badosa will next face the winner of Thursday night's marquee clash between four-time Grand Slam champion Naomi Osaka and sixth-seeded American Coco Gauff.
Elsewhere, American Amanda Anisimova beat Czech Karolina Pliskova for the first time in five attempts to reach the quarter-finals. Anisimova trailed by a set and a break on the way to a 3-6, 7-5, 6-1 victory.
Seventh-seeded Daria Kasatkina also advanced, beating American Taylor Townsend 6-4, 6-0.