TAIPEI CITY, Chinese Taipei - In her first tournament since her return from offseason knee surgery, former World No.12 Sabine Lisicki rallied into the semifinals at the Taiwan Open on Friday with a 4-6, 6-4, 6-4 victory over Monica Niculescu.

The German, now ranked World No.246, returned to tennis last June following a lengthy layoff due to a shoulder injury, but the former Wimbledon finalist revealed in January that she had would have a delayed start to her 2018 season after dealing with a knee injury following her run to the quarterfinals at the WTA 125K series event in Limoges last November.

Over the course of the quarterfinal match, Lisicki was down, but never out, as she came from a double break behind in the second set, and won the last three games of the match.

"It's my first WTA [semifinal] in a while, so I think I'm doing pretty well. I think what I did really good was fight. Even if you don't play your best tennis, but you fight and find a way to win, no matter if it's plan B, C or Z, you just find a way to win the last point."

- Sabine Lisicki

A mammoth effort from both players over two hours, 44 minutes saw a total of 227 points played and 19 breaks of serve overall. The opening set saw Niculescu land 89% of her first serves in the court, as the Romanian staved off seven of the nine break points Lisicki created in her first five return games.

A lengthy game, in which Lisicki saved a pair of break points before dropping serve set the tone for the match, as Niculescu eventually needed two more breaks of serve to edge ahead for a one-set lead.

The Romanian stemmed the tide of four straight breaks to end the set, as she dug out of a 0-40 hole with five straight points. 

"Sometimes, you forget how much love you have for the game because you just get caught up in the job. I love it so, so much so when I'm out, I feel how much I miss it, and I just enjoy it again so much more. The support of the crowd is just happiness," Lisicki said of her week so far in Taipei. 

"You start from zero - conditioning, you're slow in the beginning, so you have to build everything up from scratch."

The German has had a flair for the dramatic over the course of the week in Taipei City, and needed to conjure up some more magic to stay in the match after falling behind 3-0, with Niculescu to serve, in the second set. 

Lisicki already erased a 5-1 third set deficit in her opening round match against qualifier Zhang Yuxuan, saving two match points to win, 6-3, 1-6, 7-6(3), and saved a game point for a 4-0 deficit on the Niculescu serve en route to finally getting on the board in the second set.

The former World No.12 eventually leveled at 3-3, but needed to win the last three games to send the match to a decider after the World No.99 scored a third break of her big serve in the second set. The final set proved more of the same for both players, though this time it was Lisicki who was unable to hold on to a break advantage twice in the opening games. 

In a pivotal eighth game of the decider which saw seven deuces on the Niculescu serve, the Romanian was unable to convert on a toal of four break points which would've brought her to within one game of the semifinals, and Lisicki leveled proceedings on her fifth break point of the game.

Bouyed by her momentum, the German dropped just three points in the final two games to move through to the last four at a WTA-level event for the first time since the Aegon Classic in Birmingham in 2015.

Lisicki's increased aggression was what won out for her on the afternoon, as she hammered 64 winners over the course of the match, more than four times Niculescu's final total of 13.

That number more than balanced out the German's 56 unforced errors, and when all was said and done, she broke the Niculescu serve on 10 of her 28 oppourtunities. 

"Of course, I was a bit patchy, and sometimes I make easy mistakes, but she makes you make those mistakes. She plays a completely different game, so you have to risk a little bit more and be ready to run," Lisicki said. "I'm just happy that I came back, and any win now gives me confidence."

In the last four, Lisicki will face Ukrainian Kateryna Kozlova, who upset No.5 seed Yulia Putintseva in the day's first quarterfinal, 7-5, 6-3.

"She's a fighter and she has great defense and likes to play with spin. I knew I had to be patient today, and when I had a chance, take it. I was trying to go to the net...and I think that's why I won, because I was more aggressive in important moments," Kozlova said. "It's a good start to the season, the second tournament for me. I'm very excited to play tomorrow."

The other semifinal will see No.4 seed Timea Babos, who defeated Magda Linette, 6-1, 6-3, take on Wang Yafan, who ousted Eugenie Bouchard with the loss of just four games, 6-4, 6-0.

Babos is the lone seed among the semifinalists, and it is her fourth WTA semifinal showing in the last 12 months. Wang reaches her third semifinal at WTA International level, having gone 0-2 in her previous two.

"I think my focus today was pretty good from the start to the end of the match and I didn't have too many unforced errors," Wang said, via a translator. "I was quite happy with my forehand today. I really like this court and I think it suits my game."