Melbourne, Feb 3 (IANS): Naomi Osaka on Wednesday entered the quarter-finals at the Gippsland Trophy after securing a 3-6, 6-3, 6-1 win over Great Britain's Katie Boulter, thus stretching her unbeaten run to 13 matches.

"After I lost the first set... I wanted to fight as hard as I can. She was playing really amazing, so I thought that if I lost at the end of the day, it's okay, but I just wanted to give my best effort," the WTA website quoted Osaka as saying on-court after the match.

"I like playing long matches because I feel like I can gauge the condition of the court and that my fitness gets better. I played a short match yesterday, so maybe subconsciously, I felt like I needed to play a long match today," she added.

Third seed Elina Svitolina also reached the last eight after overcoming former French Open champion and No.13 seed Jelena Ostapenko, 6-7(4), 6-3, 6-2, in a match that lasted two hour and 12 minutes.

"It was a bit windy and it was really tough to find the rhythm, and it's not easy to play against her because she's going for a lot of shots and you have to really be on your toes," Svitolina said.

"I was a bit flat in the first set and I wasn't happy with the way I started. Afterwards, I was just trying to make an extra ball back and tried to make a difference on the balls I had a chance on," she added.

Svitolina will take on seventh seed Elise Mertens, who defeated Caroline Garcia, 7-6(1), 6-3.