World number one Angelique Kerber has expressed relief at finding the fight to overcome Shelby Rogers at Wimbledon in a third-round match she believes could be the turning point in her season.

Kerber has struggled to find her top form in 2017, reaching just one final on the WTA Tour so far this season - losing to Anastasia Pavlyuchenkova at the Monterrey Open.

The German - runner-up to Serena Williams at the All England Club last year - needs to reach the final again to retain her place at the top of the rankings but was given a real scare by her American opponent.

Already a set down, Kerber faced a break point at 2-4 in the second but raised her game in the nick of time to claim a 4-6 7-6 (7-2) 6-4 triumph and book a last-16 meeting with Garbine Muguruza.

"I found [my fight] in the second set," she told reporters. "I think it was important that I found it because, without this, I don't know if I would be in the next round right now.

"But I think that was the key in the second set, that I was really fighting and I was moving better. I was running better to every single ball. I think I started to feel the ball in the tie-break in the second set. I was playing really good.

"Then the third set was also a few up and downs, but it was better tennis also from my side."

Discussing whether the comeback could be a turning point in her year, Kerber continued: "We will see. But it was for sure a really important win for me, especially because it was a really up-and-down match. I turned the match around.

"Maybe it is a turnaround [in the season]. We will see. But for me it was really important to win this match."

Kerber and Muguruza have met on seven occasions but it is the Spaniard who edges the head-to-head record, having won each of the last four encounters, including one at Wimbledon in 2015.

"I have to play good tennis from the first point against her," said Kerber. "I have to be aggressive, as well, and try to play my game from the first ball that we hit.

"But I think it's a completely different match than the last three matches I had here.

"I'm looking forward to playing against her, trying to give my best again, trying to win against her. The last time I played her here, I lost the match, so..."