The action at this week’s ATP Challenger Tour 175 events heated up Thursday, when Aix-en-Provence top seed Tommy Paul advanced to the quarter-finals in southern France. Daniel Elahi Galan’s victory against World No. 34 Yoshihito Nishioka was one of several upsets at the Cagliari Challenger.

American Paul cruised past Frenchman Geoffrey Blancaneaux 6-2, 6-2 to reach the quarter-finals of the Open Aix Provence Credit Agricole.

“Tough conditions today, it was windy. But overall I’m happy with how I played, I wish I would’ve served better,” Paul said in his on-court interview. “More first serves in the court would’ve been better, but I’m happy to walk away with the win.”

World No. 17 Paul is the first Top-20 player to be competing at a Challenger Tour event since Stan Wawrinka played the Prague Challenger in 2020. The 25-year-old Paul will face Jurij Rodionov in the last eight. The six-time Challenger champion Rodionov advanced after outlasting Tomas Martin Etcheverry 6-3, 1-6, 7-6(5).

Andy Murray escaped alternate Laurent Lokoli 6-4, 5-7, 6-3. Despite having four match points in the second set, three-time major champion Murray was pushed to a decider by the home hope before sealing victory after two hours, 42 minutes.

Lucky loser Harold Mayot earned the first Top-50 win of his career Thursday when he upset second seed Brandon Nakashima 7-6(2), 6-3. The Frenchman Mayot will next meet Alexander Bublik, who downed Otto Virtanen 6-4, 6-4.

Two teenagers are into the Aix-en-Provence quarter-finals. Luca Van Assche, 18, rallied from a set down to beat countryman and third seed Adrian Mannarino 3-6, 6-3, 6-2. The 18-year-old Arthur Fils needed two hours, 28 minutes to oust Quentin Halys 7-5, 4-6, 7-6(2).

David Goffin also advanced in Aix-en-Provence after defeating Dan Added 6-4, 3-6, 6-2.

The upset of the day came when Colombia’s Galan defeated top seed Nishioka 2-6, 6-1, 6-4 at the Sardegna Open.

Galan, 26, is building off his career-best season. In 2022, he stunned World No. 5 Stefanos Tsitispas in the opening round of the US Open and reached a career-high No. 67 in November.

How did that feel? “Pretty good” 😁

Daniel Elahi Galan sees off top seed Nishioka 2-6, 6-1, 6-4 to secure a spot in the Cagliari quarters!#ATPChallenger

— ATP Challenger Tour (@ATPChallenger) May 4, 2023

Galan had to rally from a set down in each of his first two matches in Cagliari, where he will next face Borna Gojo after the Croatian earned a 6-4, 7-5 victory against Yosuke Watanuki.

Second seed Ben Shelton moved past Hungarian Fabian Marozsan 6-4, 7-6(6). The lefty Shelton, who is World No. 38, secured four straight points from 4/6 in the second-set tie-break to advance.

Also in Cagliari action, Thanasi Kokkinakis won 26 of 27 first-serve points to defeat Alessandro Giannessi 6-4, 6-2. The Aussie will meet fourth seed Laslo Djere in the last eight after the Serbian fended off all five break points faced to defeat Jozef Kovalik 6-4, 6-2.

Thanasi Kokkinakis in action at the ATP Challenger 175 event in Cagliari. Credit: Mike Lawrence/ATP Tour

Taro Daniel ousted third seed Mackenzie McDonald 6-2, 6-3 to book his ticket to the quarter-finals, where he will meet Ugo Humbert.

Home hope and #NextGenATP star Giulio Zeppieri has earned back-to-back wins against countrymen. After surviving Andrea Vavassori in the opening round, Zeppieri moved past Mattia Bellucci 6-2, 6-0 to set a quarter-final clash against Shelton.