JURMALA, Latvia – Sixth seed Anastasia Potapova battled through to the quarterfinals of the Baltic Open with a 6-1, 4-6, 6-2 victory over home wildcard Diana Marcinkevica.

The 18-year-old Russian said after her first-round victory over Barbara Haas that she was seeking to improve with each match and certainly impressed as she sped to the first set in just 22 minutes. Life became trickier when her opponent found some confidence and steamed back from behind to push the match into a decider, but the WTA World No.64 was able to find an extra gear to progress.

"In the second set I lost my focus and I started to play very emotionally," Potapova said, after the match. "After winning the first set pretty easily, I relaxed a little bit."

"What I really want to say is ‘thank you’ to my team," Potapova added. "It will be a lesson for me."

Initially, it promised to be a quick afternoon for Potapova, who after spending little more than an hour on court on Wednesday was imperious throughout the first set against an opponent ranked more than 150 spots below her on the WTA Ranking. Short, punchy points saw her open up an early 2-0 advantage, and though she was guilty of the type of lack of concentration that allowed Haas to gain a foothold the previous day, her play was powerful enough to negate the break.

Marcinkevica, the WTA World No.223, failed to make headway on serve in the first set, winning just five points as it slipped away amid a smattering of 12 unforced errors and crunching winners from the other end of the court.

As Potapova moved 3-1 to the good in the second, it was beginning to seem that the youngster’s progress was a formality as Marcinkevica, who had never won a WTA Tour main draw match before this week, continued to misfire on serve.

By the time the underdog finally won a game on her own delivery, she was already a break down. However, she was visibly lifted by reaching this milestone and fueled by an increasingly vocal home crowd, was able to hit herself back to parity, becoming a player transformed once on terms. 

Her increased confidence and positivity was only highlighted by the manner in which she aggressively struck a winner off a weak second serve to seal the set.

With seeds having tumbled all week, Potapova may have feared she would be the latest victim but her opponent’s burst proved little more than a purple patch. Two quick breaks early in the decider pushed the seeded player clear, and though the Latvian was able to claw one of these back as she showed glimpses of her best play, she was unable to reprise it fully, even amid a let down from her opponent.

Another break followed amid a spate of missed first serves from the home player, leaving Potapova to serve out and seal a last-eight meeting with the in-form Patricia Maria Tig and a potential semifinal with another Latvian, top seed Anastasija Sevastova.

"[Tig] is a good player, and I think that the match will be tough," Potapova stated. "I’m going to do my best and we will see what happens."