OSTRAVA, Czech Republic - An all-unseeded quarterfinal at the J&T Banka Ostrava Open found Maria Sakkari coming from a set and a break down to deny Ons Jabeur a breakthrough beyond this stage, triumphing 3-6, 6-3, 6-1 to reach her second semifinal of the season in one hour and 38 minutes.

The Greek player, who also made the last four indoors in St. Petersburg in February, trailed by a set and 0-2 in the face of some sparkling form from Jabeur - but a near-perfect service game was the trigger for a brilliant turnaround in which Sakkari won 12 of the last 14 games, committing just six unforced errors over the last two sets.

"I think that Ons, she came up with some tricky shots in the first set - I couldn't really find a way to make her life tougher," mused Sakkari afterwards. "But just the fact that I know I can stay on court for a long time gives me a lot of help and hope, so I just said, stay with her, stay with her, and finally I got that break I was looking for - and things got better for me after that."

For Jabeur, though, the satisfaction of demonstrating newfound consistency in her breakthrough season by reaching a fifth quarterfinal will be balanced by disappointment at losing each of her matches at this stage, having also fallen in the last eight of the Australian Open to Sofia Kenin, Doha to Petra Kvitova, Lexington to Coco Gauff and Cincinnati to Victoria Azarenka.

As in her defeat of Jelena Ostapenko in yesterday's second round, Jabeur's commitment to high-risk tennis meant that there was a thin line between winners and unforced errors - and in the first set, the World No.32 was also able to play within herself when she needed to maintain scoreboard control. The most important points of this passage of play invariably found Jabeur's execution on point, both in terms of the basics and her highlights reel specials.

A service winner fended off a break point in the first game, and though Jabeur's trademark dropshot was hit-or-miss in the opening stages - particularly in the face of Sakkari's athleticism in tracking them down - sticking at the tactic only made it better as the set went on. The sixth game saw Jabeur blaze a forehand winner down the line to bring up her own first set of break points, and she would eventually convert as a short slice elicited a backhand error from the Greek No.1.

As Jabeur closed out the set, her game reached delirious heights: serving for it, she was able to steer Sakkari from line to line before finding some spellbinding finishing shots, including the single-handed inside-out short backhand slice winner with which she reached set point.

More superb controlled aggression garnered Jabeur an immediate break in the second set, but signs were growing that Sakkari was beginning to raise her level - not least the near-perfect service game comprising three aces and a service winner with which she got on the board in this frame. When Jabeur's form dipped with a flurry of unforced errors in the sixth game, dumping a short forehand into the net to hand the break back, Sakkari - who committed just one unforced error of her own in this set - was perfectly poised to take advantage.

Indeed, that dream hold would trigger a run of 10 of the next 11 games for the 25-year-old, and it would be her turn to conjure up some magic at the tail end of the second set: a spectacular drop volley at full stretch in the seventh game, a no-holds-barred return winner en route to breaking for 5-3 and finally a solid one-two punch on her first set point.

There would be no let-up from Sakkari in the deciding set: the World No.23 held her ground on the baseline to begin dictating groundstroke exchanges. Forced on to the defensive, Jabeur's game started to break down: having controlled her aggression so well in the first half of the match, the 26-year-old began to strike out rather too wildly, with over-ambitious dropshots barely reaching her own side of the net and unforced errors mounting up to a final tally of 39.

A tame double fault put Jabeur down a double break, and the 2018 Moscow finalist failed to take advantage of an opportunity to get back into the match in the next game as Sakkari saved a break point with a service winner to move up 4-0. That would prove to be Jabeur's last stand: Sakkari's solidity never looked like cracking again as she eased over the finishing line, taking her first match point with a forehand pass that was beyond even Jabeur's famed hand skills to deal with.

Next up for Sakkari will be former World No.1 Victoria Azarenka - a legend of the game whom she will meet for the first time. "Vika is a great champion, she has achieved unbelievable things in tennis. It's going to be a very tough match for me, but I'm really looking forward to it," she said.

2020 Ostrava Shot of the Day: Kudermetova superb drop shot