Petra Kvitova played dynamic tennis defeating Serena Williams in a three-set Cincinnati blockbuster.
It was the two-time Wimbledon champion's second straight win over Williams.
More: Kvitova Wins Cincinnati Epic
So what's the key to conquering the 23-time Grand Slam champion?
Kvitova cites two essential elements to beating the former world No. 1: hold serve and commit complete mental focus to every point.
"It's fun to play, for me," Kvitova said. "It's not about the forehand or backhand or serve. It's like a mental game, as well, you know, still staying there and be focusing on every point.
"You need to play well, you need to serve well, because she's serving well almost every time." So it's just about the staying really very focused and every single point."
The sixth-ranked Kvitova, who will face Kristina Mladenovic next, said she often brings her best against Serena because anything short of her best will not get it done.
"I think that I need to play my best if I want to beat her," Kvitova said of Williams. "I'm pretty lucky when I'm playing these kind of players and always playing great. Not always, but most of the time. So it's nice that I can show the best tennis against the best players."
Photo credit: Western & Southern Open Facebook