ISTANBUL, Turkey - A cerebral first-round clash at the TEB BNP Paribas Tennis Championships Istanbul found Anna Karolina Schmiedlova get the best of Kaja Juvan 7-5, 1-6, 6-4, closing out the win on her fifth match point after two hours and 18 minutes.

Though on paper a contest between two unseeded players outside the Top 100, this first encounter between former World No.26 Schmiedlova, on the comeback from a knee injury that sidelined her in the second half of 2019 and fresh off the Prague 125K quarterfinals last week, and fast-rising 19-year-old Juvan, already with victories over Venus Williams and Marketa Vondrousova this year, made for an intriguing and ultimately high-quality tussle.

"I know my opponent, she's very young and a very clever player, especially on clay," said Schmiedlova afterwards. "I was just telling myself to be brave, to be aggressive and that I have to finish it myself. It's difficult for me, because I'm a defensive player and I feel really good when I'm running. But I know that in WTA tournaments I have to be more aggressive, to change the direction of the ball down the line more. I'm happy with how I managed it at the end, because I lost that tough game when I was 5-3 up - but then I found another strength to fight again.

"It's very difficult for me to find that bravery, but I think I found it today."

This year's pandemic had particularly unfortunate timing for Schmiedlova, who did not play after Wimbledon in 2019 due to knee surgery. While many other players have spoken about the pause being an unexpected opportunity to refresh themselves mentally, Schmiedlova had just done that. "I did many things I was dreaming about when I couldn't play tennis," she said. "I travelled, I took some time off, I had really great preparation after the knee surgery. I did everything I wanted and I was really ready at the beginning of the year to play. I had a lot of energy, I was playing tennis without pain again, and I was especially looking forward to the clay tournaments."

Nonetheless, the thoughtful Slovak kept herself busy - with both her beloved art, which helps take her mind off tennis during tournaments, and her involvement in Postavme Sa Spoločne (Let's Stand Together), an anti-racist campaign in Slovakia in response to the rise of the far right.

"It was to remember the Holocaust and fight against racism," Schmiedlova, who has been following Naomi Osaka's activism this month with admiration, explains. "I tried to find other athletes to help with this video and this movement because many other people also felt they should talk about it. I feel it's really important, as an athlete, to stand up when you believe something, especially in these times. It's important to talk about tolerance and anti-racism. I strongly believe in what I think about these things."

Today, Juvan struck first, deploying the dropshot to audacious effect to capture the Schmiedlova serve off the bat - but it was the Slovak who surged into a 3-1 lead. Superlative Schmiedlova defence got her the break back immediately and appeared to rattle Juvan, who lapsed into a temporary bout of errors.

The teenager managed to keep at Schmiedlova's heels, finding particular success when coming forwards - but the three-time WTA titlist managed to keep her nose in front through first a four-break sequence, and then four holds in a row as both players tightened up their play behind their serves at the business end of the set. Schmiedlova was showcasing a perfect blend of offence and defence, and using the geometry of the court exquisitely during a number of lengthy, quintessentially claycourt exchanges.

In the end, a rare mistake from Juvan decided the set: facing a second set point as Schmiedlova upped the ante on return, the World No.113 lost her touch on the dropshot for one of the few times today, crying out in frustration at such an uncharacteristic error on such a key point.

However, the Slovenian would use the disappointment as fuel to storm to a near-perfect second set. Redoubling her aggression, Juvan slammed a pair of winners down the line to seize a double-break lead, and swarmed the net at every opportunity with superb results. But Schmiedlova managing to make a belated impact on the stanza would prove significant. The 26-year-old would save a point for the bagel and land a few blows before Juvan closed out her third set point by blitzing a backhand winner down the line.

Heading into the decider, it was this momentum that Schmiedlova sustained. Rejuvenated, the World No.182 captured the Juvan serve twice in the first three games, the second time after taking her sixth break point of a mini-marathon, and built a 3-1, 30-0 lead.

Gallery: Great Escapes 2020: This season's match point saves

Juvan is a relatively new face on the WTA Tour, having made her debut at this level at Roland Garros last year - but she has already garnered a reputation for tenacity when behind. Indeed, the former junior World No.5 currently holds the record for the most number of match points saved en route to a WTA Tour victory in 2020, staving off a remarkable seven against Venus Williams in Acapulco this February. This spirit was very much in evidence as she surged back to level at 3-3, and then fended off triple match point serving at 3-5 - one with a scintillating forehand winner in the corner - to pile the pressure on Schmiedlova.

But although the final game was another knife edge, Schmiedlova held firm, landing her first serves when she needed to and sealing her fifth match point as Juvan found the net with a backhand.

Elsewhere, No.5 seed Heather Watson was forced to retire due to dizziness while trailing Sara Sorribes Tormo 2-3 in the first set, while Jasmine Paolini needed two hours and two minutes to overcome Stefanie Voegele 6-1, 4-6, 6-3. No.3 seed Polona Hercog, a runner-up in Istanbul in 2018 (at a different venue) was the highest-ranked player on court on Day 1, and lived up to her status with a 6-2, 6-3 defeat of 20-year-old No.387-ranked Turkish wildcard Berfu Cengiz, who was making her WTA main draw debut.

2020 Istanbul highlights: Schmiedlova ousts Javan