WUHAN, China - Qualifier Monica Puig has stunned No.2 seed Caroline Wozniacki for the second time this year in the third round of the Dongfeng Motor Wuhan Open, pounding her way into the quarterfinals 7-6(10), 7-5 in two hours and 24 minutes.

Though the Puerto Rican had trailed Wozniacki 2-3 in the overall head-to-head before today, she had scored a memorable upset in their most recent meeting, coming from a bagel set down to defeat the Australian Open champion 0-6, 6-4, 6-4 in the second round of Miami. The 24-year-old also came into today's match in strong form, having won 13 of her past 16 matches - including a semifinal showing in New Haven and a quarterfinal in Québec City.

“I feel like we've played each other several times now,” Puig said. “I think Wozniacki is maybe one of the only players I've played so frequently against on the tour. We definitely have had our fair share of battles throughout the times that we've played.

“We both know each other's game very well… I just had to try to stay focused and be really aggressive on those certain key points that I wasn't today at some times, but I was happy I was able to get it out.”

The first set initially seemed to be going much the same way as in Miami. Puig coughed up 11 unforced errors in the first three games, struggling to find the range on her groundstrokes or return, and swiftly fell behind 0-3. But as Wozniacki held two points for a 4-0 lead, Puig would finally hammer a backhand winner - one of many that would flow from this wing today - and the Dane double faulted.

This invitation to gain a foothold in the match was unexpected, but the Rio Olympic Games gold medallist took it eagerly. Suddenly, the aggression that had initially seemed over-eager was resulting in a cascade of winners - 24 in the set - and putting her in control; her groundstrokes were holding up enough to puncture even Wozniacki's indefatigable defence; and her first serve, missing to start with, was betting her free points.

As Puig broke again to take a 4-3 lead, she would even begin to deploy a strategy of judicious net play to excellent effect, bringing the former World No.1 in with a dropshot before putting her own volley away, and more exquisite net play paved the way to another break for 6-5.

Though the World No.51 would frequently find her best tennis when playing from behind, the same was not always true when she was ahead. Both of her first-set leads were conceded immediately, and closing out the first set proved to be something of a struggle. One set point came and went as Puig served for the set, thanks to an errant forehand; a 6-3 lead in the tiebreak dissipated as, unable to adjust to a net cord, she sliced a forehand into the net.

But the New Haven semifinalist was resilient even when it was her turn to stare down the barrel of defeat, coming up with two brilliant points to save a brace of set points - and, after Wozniacki double faulted on her third, Puig at last powered away a drive volley to take a dramatic tiebreak on her sixth to seal a 78-minute opener.

Wozniacki would be unusually error-prone over the course of the whole match, committing 16 unforced errors in each set, but the second set saw the two-time US Open runner-up begin to up the aggression on her own groundstrokes, with a drive volley and a brilliant backhand down the line giving her a 2-0 lead.

But once again, Puig would be at her most dangerous when behind, and Wozniacki was unable to take two points for a 4-2 lead as the Monterrey and Québec City quarterfinalist hit back with her 14th successful net foray of the day and then a phenomenal backhand return winner.

The second set continued to mirror the first act to the end: a Wozniacki lead pegged back by Puig, and then a dramatic climax as the latter attempted to get over the line. Serving to stay in the match, Wozniacki continued to leak errors, with a smash into the net giving Puig a first match point.

But the World No.2 would save three in this game - two with winners of her own and one as Puig overpressed, raising her own tally of unforced errors to 50 - and, remarkably, another three as she served to stay in the match for a second time.

Eventually, though, it was seventh time lucky for Puig, who found the court with a forehand winner - her 37th of the day - to progress to the first Premier 5 quarterfinal of her career.

“That's the one thing I'm trying to work on with my team as much as possible: no matter what's going on in the match, just continue like if nothing ever happened,” Puig said of seeing all those match points come and go. “That's not always easy, especially in moments where you want to really pull your hair out.

“Honestly, on the match points that I had, I thought she played really aggressive. She really took it to me. But whenever I lost those points, would go back and go, ‘There's another point to play, still tennis left to be played. Don't get caught up in that one point because that one point, either you're going to let it dictate the rest of the match or you're going to put it in the past and move forward.’”

In the quarterfinals, Puig - who sealed the fifth consecutive Centre Court match in which the lower-ranked player emerged the victor in Wuhan today - will face home favorite Wang Qiang in an all-unseeded battle.

“I don't think I've played [Wang] in a tournament, but we have practiced against each other," Puig said. "She's a very nice girl. I have a lot of respect for her, especially with what she's been doing in the past couple weeks. She won last week in Guangzhou.

“Just practicing with her, she hits a big ball. She can do whatever she wants with the ball if you give her the opportunity. She's definitely going to be a tough test for me, especially her playing at home, she's going to have the home-court advantage.

“I'm just looking forward to getting out there and continuing to play. I'm having a lot of fun right now. Tomorrow is my birthday, but I just want to enjoy it as much as possible.”