Kim Clijsters promised to plough ahead with her ambitious comeback despite losing her return match in the opening round of the Dubai Duty Free World Tennis Championships.
Four-time Grand Slam champion Clijsters, 36, had been out of the game for seven years before the clash with Garboine Muguruza, who reached the final of the Australian Open last month, and is keen to push on after an encouraging display against the world number 16 Spaniard.
She eventually lost 6-2, 7-6 (8/6) to Muguruza, but said: "I had a good feeling out there, I felt a pace I can handle. I felt like I was able to go toe-to-toe with her from the baseline.
"I wouldn't have done this if I didn't have that belief somehow. It might take 10 matches to get the way I played in the second set, might take me 10 matches to get that from start to finish.
"I have patience. I'm going to work my way into it and fight. We'll see what happens."
Clijsters did not say where she will continue her comeback, not mentioning any future tournament entries after taking part in Dubai as a wild card.
Two-time Grand Slam winner Muguruza meanwhile will play one of Veronika Kudermetova and Dayana Yastremska in the next round after having to fight off a determined Clijsters in a tight second set following a simple first.
"I've seen her play when I started on the tour, she's an incredible player," Muguruza said of Clijsters.
"I was excited to be the first (opponent of the comeback). She played very well, especially in the second set.
"At the end. It was very tight. It was a fun match to play.
"I'm sure she's going to get better and better, for sure she give me a lot of trouble. She played really well after all these years (away)."
Ninth seed Muguruza, 10 years younger than Clijsters, dominated early on as the veteran Belgian played her first official match since the 2012 US Open.
Mother of three Clijsters, who was playing in Dubai for the first time in her career, was on the back foot in the early part of the match, losing serve in the first game of both sets.
She found herself three down after losing her first two service games in the second set after being swept aside in the first but fought back gamely to lead 5-4 after nine games.
However Muguruza took the set to a tie-break and emerged victorious with a service winner on her second match point after nearly an hour and three-quarters on court.
Earlier, Ons Jabeur beat Alison Riske 7-6 (7/3), 1-6, 6-3 to earn a second-round date with top seed Simona Halep.
Tunisian Jabeur, ranked 45 in the world, saw off American Riske amid passionate home support for a player who trains in Dubai.
"I'm so grateful for the crowd, they really gave me energy. It feels like home here," said Jabeur.
"Alison is tough, she made me run everywhere, I was down in the second set but got it back in the third," added the first Arab woman to reach a Grand Slam quarter-final last month at the Australian Open.