Top seed Tommy Paul edged into the quarter-finals of the Adelaide International with a three-set victory over Manuel Guinard on Wednesday, with Felix Auger Aliassime also advancing.

Paul will face home favourite Rinky Hijikata next after resisting a defiant fightback from Guinard to seal a 6-4 3-6 6-3 second-round win.

Paul, who achieved his best grand slam performance by reaching the Australian Open semi-finals in 2023, was playing his first match of 2025 as he warms up for the Melbourne Park slam.

The American broke in his first game of the year en route to taking the opener, and though Guinard picked up in the second set, Paul put his foot down in the third after breaking in the second game.

"The first match is always such an important one to feel where your level is," said Paul. "I felt like I dealt with the pressure points pretty well and I'm looking forward to the next match."

He will be joined in the quarter-finals by Auger Aliassime, who fought back for a 1-6 6-4 7-5 win over Arthur Cazaux and will face Marcos Giron next.

Paul's compatriot Sebastian Korda will take on Australia's Thanasi Kokkinakis in the last eight following their respective wins over Alejandro Davidovich Fokina and Tomas Martin Etcheverry, while Miomir Kecmanovic will play Benjamin Bonzi.

At the Auckland Classic, meanwhile, top seed Ben Shelton lost 7-6 (7-2) 4-6 7-5 to Jakub Mensik, leaving seventh seed Nuno Borges as the top-ranked player to reach the last eight.