NEW HAVEN, CT, USA -- No.5 seed Julia Goerges of Germany went deep into the early morning before outlasting 18-year-old qualifier Dayana Yastremska of Ukraine, 6-4, 3-6, 6-4, in the second round of the Connecticut Open.

"I just tried to stay focused, it was pretty late today," Goerges told the media, after her win. "I just managed to come back in the third set, to really play my game again, to take a little bit of the momentum away from [Yastremska]. I think at the end, I used my experience to know how to break at 5-4, and I’m just very happy that I’m still here."

"I’d rather have these kind of matches and really pull them through, tough ones," Goerges stated. "I think those matches are exactly the ones I want to have before the US Open."

Goerges, who reached her career-high ranking of World No.9 on Monday, had to dig deep against the Ukrainian youngster, and ultimately prevailed in two hours and 22 minutes, coming back from a break down in the final set. Goerges won over two-thirds of points on Yastremska's second service.

Yastremska acquitted herself well throughout her first-ever match against a Top 10 player, slamming 28 winners -- four more than Goerges. But she gave up one more break of serve than Goerges did, which made the difference in the deciding set as Goerges pulled ahead from 0-2 down.

"It took a little bit of time for me to adjust and see her game, and I think at the end I did it really well to read her balls, and really took advantage out of her shots," the World No.9 explained.

"I think the difference at the end was the experience," Goerges also said. "I think she’s going to have a bright future, she has really good shots, and she knows what she wants to do on court."

Goerges moves into the quarterfinals of a WTA event for the eighth time this season. There, she will face either Ekaterina Makarova of Russia or Magdalena Rybarikova of Slovakia.

The fifth seed took the initial lead, breaking the Ukrainian teenager at love for a 3-2 lead, but Yastremska struck back immediately, using deep, aggressive returns to flummox the big-serving German and level the set at 3-3.

A long game then ensued on Yastremska’s serve, where the Ukrainian fell behind triple break point, which included a second point of the game where a down-the-line winner by Goerges sent Yastremska tumbling to the ground after she tried to change direction.

But Yastremska clawed her way back to deuce, including a second-service ace at 30-40. The teen saved another break point en route to two game points, but powerful forehands by the German erased those chances. Eventually, a backhand return winner by Goerges brought her a fifth break point, which she converted, taking a crucial 4-3 lead.

That would be the definitive break Goerges needed, and the No.5 seed overcame a brief rain delay at 5-3 to close out the set 6-4. Goerges had 10 winners and 10 unforced errors in the set, while Yastremska’s eight winners were outpaced by her 11 unforced errors.

But Yastremska received good fortune at the very start of the second set, when Goerges threw in a shocking service game at 1-0, firing three double faults to get broken at love. Yastremska took advantage, holding serve comfortably to reach a quick 3-0 lead.

The aggressive youngster had no trouble on her serve throughout the rest of the set, dropping only three points in her three remaining service games. Goerges saved three set points on her serve at 5-2, but forcing Yastremska to serve out the set instead had no effect, as the Ukrainian tied up the match on her next set point.

The fiery returns of Yastremska continued in the deciding set, and she broke Goerges in the opening game on her third break point with an overhead winner. But Goerges finally reclaimed the efficacy on her fearsome forehand, blasting from that wing to get the break back for 2-2.

As the set wore on, the experience of Goerges seemed to outweigh the risk of Yastremska, and the German withstood a mid-game fightback from 0-40 down to claim a second break and lead 4-2. After another wicked forehand forced a long error from Yastremska to give Goerges a 5-2 lead, the German seemed in control.

But the teenager was not done yet, and held her nerve to break an error-prone Goerges at love when the World No.9 served for the match at 5-3. But Yastremska finally succumbed to the pressure while serving to stay in the match, and sent two consecutive forehands awry to give Goerges an extremely hard-fought victory over a rising star.