BIRMINGHAM, Great Britain - Hsieh Su-wei carved her way through to another upset on Monday, this time in the first round of the Nature Valley Classic.

The World No.28 upset artist sealed a 6-3, 2-6, 7-6(1) victory over No.5 seed and World No.10 Aryna Sabalenka for her fourth Top 10 victory of the season and seventh of her career.

Hsieh came from a break down in the final set to score her second career victory against Sabalenka, rallying from a 4-2 deficit and dominated the ensuing tiebreak, winning all of Sabalenka's service points. 

"It was not easy because it's my first match on the grass court. I knew it was going to be really tough, so I just got ready for anything to happen on the court," Hsieh said.

"It's not easy because you know she can make any winner from anywhere; serve, return, baseline. She was slicing pretty good. I was surprised.

"I [said] 'Okay, I cannot do stable and try to play my stuff,' so I was doing very good to keep concentrated on my game."

Hsieh broke Sabalenka twice in the opening set, and never faced break point herself, en route to building a lead, but the big-hitting Belarusian returned the favor in the second set.

She broke twice, and saved the lone break point she faced, to win her first set against the 33-year-old from Chinese Taipei in their second meeting, but proved unable to seal her first grass-court victory of the season after a first-round exit at the Libéma Open last week. 

Though Sabalenka won 70 percent of the points played on her first serve, and hit eight aces in the match, she proved vulnerable behind her second delivery.

The World No.10 served four of her six double faults in the match in the final set, and managed to win just 41 percent of the points when she needed to hit a second serve overall.

"I never beat, like, a Top 10 or Top 20 a lot before. Some of the matches I was leading a lot, I was winning first set 3-Love, second set, and I just crack and it never happened," Hsieh said.

"I tried to stay cool, smile and say 'Okay, whatever, anything can happen.' I just need to be positive and try my best and it was helping a lot because against a big player."

Hsieh advances to take on good friend and doubles partner Barbora Strycova, last year's finalist in Birmingham.

The Czech came from a set down to defeat wildcard Heather Watson, 3-6, 6-3, 6-4.