ROME, Italy - No.11 seed Elise Mertens made a solid transition from hardcourts to clay on Monday, kicking off her Internazionali BNL d'Italia campaign with a 6-3, 6-1 win over Hsieh Su-Wei.

"I'm not sure how well I adapted, to be honest!" Mertens admitted in her post-match press conference. "I just feel like I might still be struggling a little. It was also her first match of the week, so that was a bit of an advantage for me. Going from hard to clay is a little difficult with the sliding and timing, but I tried to give everything I had today, tried to adapt where I could.

"The second set was definitely better than the first for me, but it wasn't my best game."

Mertens was fresh off a second straight US Open quarterfinal result, and navigated a tricky opening set to dispatch the current WTA Doubles Co-No.1 in one hour and 12 minutes on Pietrangeli court.

"You can expect a lot of different shots: dropshots, slice, a lob if you come to net. You can expect some really good shots, but I tried to mix it up too because I think she likes the hard-hitters, so she can use the pace and get her variety going. I think I did everything well today. My serve was better in the second set, which made all the difference."

Hsieh has enjoyed a revelatory 18 months in singles, finishing just outside the Top 30 in 2019 after reaching the Dubai Duty Free Tennis Championships semifinals and the last eight at the Miami Open, and has continued that form in doubles this season, winning three titles with Co-No.1 Barbora Strycova.

In search of a first singles with of 2020, she was in for a tough battle with Mertens, another double threat who won their most recent singles clash in three sets at the Toray Pan Pacific Open last fall.

The Belgian, who finished runner-up to Simona Halep at the Prague open earlier this summer and shocked reigning Australian Open champion Sofia Kenin in Flushing Meadows, was ultimately first out of the gate against Hsieh, breaking for a 2-0 lead.

Though Hsieh soon leveled up proceedings, Mertens was undeterred, breaking again with the help of some deft touch off the forehand side and won a fourth straight game to find herself a set from victory.

Rallying from a break down to start the second, the World No.20 reeled off six straight games to close up the contest in just over an hour.

In all, it was a solid match from Mertens, who struck 17 winners to just nine unforced errors, converting six of 11 break point opportunities while saving three of five on her own serve. While Hsieh made 11 winners of her own, she was ultimately undone by 22 unforced errors and eight double faults.

Up next for Mertens is Poland's Magda Linette, who defeated 2017 French Open champion Jelena Ostapenko in straight sets earlier in the day.

"I played her before, but that was years ago, so I can't really say anything. I have to look at her matches because it's been so long. I have to look at myself, too, and how the transition from hard to clay isn't easy. I had my first practices on Saturday and Sunday, but I have another practice day tomorrow."

2020 Rome highlights: Mertens masters Hsieh