Iga Swiatek had a victorious clay-court debut for the 2024 season on Thursday, when she defeated Elise Mertens 6-3, 6-4 in the second round of the Porsche Tennis Grand Prix.

World No.1 Swiatek, playing her first match on the dirt since she won last year's Roland Garros title, needed 1 hour and 33 minutes to hold off 30th-ranked Mertens and claim a spot in the Stuttgart quarterfinals for the third straight year.

The winner speaks: "I'm really happy with the way I played," Swiatek told the press. "First match on clay, so it's always tricky. Elise was really good. Sometimes at defense I had to be patient and really work for the points. So I'm happy with the way I handled it. 

"That's one of the things you have to switch from hard court, you have to be ready for longer rallies and for players to be able to get back more. And also, I can use that. I can also get back more balls. So it works both ways, but you have to switch that mindset to be more patient."

Fast facts: Two-time defending champion Swiatek remains undefeated at the Porsche Tennis Grand Prix, improving to 9-0 at the event with her latest win over Mertens of Belgium. Poland's Swiatek has defeated World No.2 Aryna Sabalenka in each of the last two Stuttgart finals.

Mertens has accrued many victories in her career, including seven wins over Top 5 opposition, but this was surprisingly her first meeting with Swiatek in singles. Swiatek held sway in their first showdown, converting four of her six break points.

Major champion clash awaits: Swiatek will next face 2021 US Open champion Emma Raducanu in the quarterfinals. Raducanu defeated Linda Noskova 6-0, 7-5 to clinch her spot in the elite eight.

The showdown between the Grand Slam champions will be a rematch of their 2022 Stuttgart quarterfinal, which Swiatek won 6-4, 6-4. Four-time major champion Swiatek also defeated Raducanu 6-3, 6-1 at Indian Wells last year to take a 2-0 lead in their head-to-head.

Match moments: On Thursday, powerful groundstrokes propelled Swiatek to a dominant 5-1 lead in the first set, as she was laser-focused on keeping her Stuttgart winning streak alive. However, Mertens got a handle on her returns as the set progressed and made a late charge to 5-3.

Swiatek fell behind 0-30 in her next service game to give Mertens hope of getting back on serve, but the top seed blasted her way to four straight points and clinched the one-set lead after a Mertens backhand flew long.

After an early exchange of breaks in the second set, an ill-timed double fault by Mertens ceded a break to Swiatek, with the Pole moving ahead 4-3.

At 5-4, incredible defense by Mertens helped her withstand Swiatek’s first three match points, but the World No.1 would not be denied, crunching a forehand winner to convert her fourth chance and sail into the quarterfinals.