Dubai: Unseeded Belinda Bencic gave Swiss fans a taste of what is to come with a hard-fought 6-4, 2-6, 7-6 (7) win to knock out eighth seed Aryna Sabalenka and make the quarter-finals of the Dubai Duty Free Tennis Championships, late on Wednesday.

Part of the team that helped Switzerland successfully retain the season-opening Hopman Cup in the company of Roger Federer, Bencic put up a valiant fight to turn the match around with her back literally against the wall.

With both players tied at one set all, Bencic was down 3-5 in the deciding third. But the 20-year-old Swiss broke back to draw level 5-5 to take the match into the tie-breaker.

Once again, she was nearly down and out as she trailed the hard-hitting Sabalenka 1-4. And yet again she came back to draw level at 5-5 to finally go on to win the tie-break 9-7, sending out a delightful shriek and sinking to her knees at the end of nearly two and a half hours of high-intensity tennis.

“I am not sure why I won and how I won today. I came here to play well and that’s exactly what I did,” Bencic told spectators who had stayed back late into the night.

“She [Sabalenka] hits so hard and I was against the wall. And the only thing I could do tonight was fight my way through and do whatever I could to just stay in the match. I survived,” she added.

Bencic’s next opponent will be Simona Halep, one of three former champions who are still in the draw. “I think this match has given me a lot of energy to play her [Halep],” Bencic joked.

“I am happy with what I have achieved in this tournament, and anything that follows from here on will be a bonus to me. I have nothing to lose,” she added.

Earlier in the day, two-time defending champion Elina Svitolina had led the march of champions in the quarter-finals, although in contrasting ways. After 2015 champion Halep and 2013 champion Petra Kvitova had eased their way to wins against Lesia Tsurenko and Jennifer Brady, it was left up to the puny Svitolina from Ukraine to power her way to a 6-1, 6-2 emphatic result in just 62 minutes against former world number one Garbine Muguruza for her 15th win in Dubai.

Going into to week, the Dubai tournament had this year boasted of five former champions, including Svitolina, Kvitova and Halep. However, 2011 champion Caroline Wozniacki pulled out with a viral illness before her first match on Monday, and 2016 champion Sara Errani – one of the four wild cards - went down in three sets to Serbian qualifier Ivana Jorovic.

Thursday’s play will commence at 2pm with Taiwan’s Su-wei Hsieh facing fourth seed Karolina Pliskova followed by second seed Petra Kvitova taking on Viktoria Kuzmova. The second session starting at 7pm will see third seed Halep up against Bencic/Sabalenka followed by Carla Suarez Navarro playing Svitolina.