MELBOURNE, Jan. 23 (Xinha) -- Now in the quarter-final stages of the tournament, day nine of the Australian Open on Wednesday was jam-packed with drama, action and injuries.

In what was described by commentators as the comeback of a lifetime, Czech world number seven Karolina Pliskova survived four match-points in the third set against 23-time Grand Slam champion Serena Williams to eventually win the contest 6-4, 4-6, 7-5.

"Of course when the score is 5-1 against you in the final set, you don't think you can win," Pliskova said.

"But I just went for it. I just said, maybe this match is over, but let's just try to win this game."

"I was with the wind, which kind of helped me little bit. I just went for my shots. She got a little bit shaky in the end so I took my chances and I won."

In the day's other women's match there was no such problems for Japanese sensation Naomi Osaka.

Last year's U.S. Open winner cruised to victory in straight sets against Ukrainian sixth-seed Elina Svitolina, 6-4, 6-1.

In the men's bracket world number one Novak Djokovic remains on track to claim a record seventh Australian Open title after his opponent Kei Nishikori retired with a quadricep injury.

Battling through three five-set marathons during the tournament and spending almost 14 hours on court before tonight's match, the battle-worn Japanese veteran pulled out of the contest in the second set with the score 6-1, 4-1.

"Before the match, I was okay," Nishikori said. "Of course, I wasn't fresh but I thought I was going to be okay."

"After third game or fourth game when I was serving, my right leg felt heavy. After that I couldn't really bend my knees and couldn't jump up, so I decided to stop."

In the other men's quarter-final match up, 24-year-old Frenchman Lucas Pouille beat out hard-hitting Canadian Milos Raonic in four sets 7-6 (7-4), 6-3, 6-7 (7-2), 6-4.

Despite never getting out of the first round in his past five appearances at the Australian Open, the world number 31 now finds himself just one match away from the tournament final.

"We kept working hard," Pouille said. "It has been a matter of going step by step and to give all that I have in every point and here we are, so I'm just really happy."

Also today, China's Zhang Shuai and her Australian partner Sam Stosur won a thrilling 7-5, 4-6, 7-5 victory in their semifinal match up against Czech duo Barbora Strycova and Marketa Vondrousova.

The pair will now take on reigning Australian Open champions Timea Babos from Hungary and Frenchwoman Kristina Mladenovic in the final.