RABAT, Morocco - Hsieh Su-Wei broke new ground at the Grand Prix de SAR La Princesse Lalla Meryem, easing past Ukrainian teenager Katarina Zavatska, 6-1, 6-1 to reach her first WTA clay court semifinal.

Playing just her second career quarterfinal on clay, Hsieh dropped just two games in the 59 minute clash, striking 21 winners to just 12 unforced errors and broke serve six times.

"She's a great young player, but I just tried to play my game today," she said during her on-court interview. "I did pretty well to put pressure on her, I think. I'm happy to get into the semifinals."

The former World No.23 began 2018 ranked outside the Top 100 before reaching the semifinals at the ASB Classic and upsetting two-time Grand Slam champion Garbiñe Muguruza en route to the Australian Open fourth round.

Surging back into the Top 60, the veteran from Chinese Taipei has seen further success in both singles and doubles this season, partnering Barbora Strycova to win the BNP Paribas Open title and reaching the third round of the Miami Open, where she pushed former No.1 Karolina Pliskova to a third set tie-break.

It was nonetheless a stellar debut for Zavatska. The 18-year-old won her maiden WTA main draw match, earned a solid win over former World No.26 Alexandra Dulgheru to reach the last eight, and will likely crack the Top 200 for the first time in her career as a result of this week in Rabat.

Standing between the No.8 seed and a first WTA final since 2012 - and a possible return to the Top 50 - is top seed Elise Mertens, who was similarly efficient in knocking out former French Open finalist Sara Errani, 6-3, 6-1.

"Every match is different and always tough, because everyone has a different game. I'll just try to be myself, try to be free and happy to enjoy the match."