Steffi Graf could have beaten Serena Williams because of American's 'one weakness', claims Andrea Petkovic

Serena Williams could have been beaten by Steffi Graf, suggested former WTA No. 9 Andrea Petkovic recently. According to Petkovic, her German compatriot had one particular weapon in her arsenal that would have likely exposed a rare chink in the American's armor.

Petkovic, a seven-time WTA Tour-level titlist, made an appearance on a recent episode of The Rennae Stubbs Tennis Podcast. During her candid conversation with host Rennae Stubbs, who coached Williams for the 2022 US Open, the former WTA No. 9 said she would put money on reigning No. 1 Aryna Sabalenka to beat the 23-time singles Grand Slam champion in her prime.

"The only player I think could have beaten her (Serena Williams) at her peak, if I had to bet, I would always put my $100 on Aryna," Petkovic said. (from 41:28)

The German then went on to briefly talk about Steffi Graf, and how the 22-time singles Major winner's slice was a shot that could have troubled Serena Williams. The legendary American is widely regarded as one of the most complete players in tennis history. However, she sometimes found it hard to deal with rivals who could play the slice well. Petkovic cited the example of Williams' 2015 US Open semifinal loss to Roberta Vinci.

"But I do think on a random day, Steffi Graf could have beaten her, just because of the slice, where Serena would be bothered by disruption of rhythm however, because she lost to Vinci that year," Petkovic added.

At the 2015 US Open, Williams looked on course to complete the Grand Slam, the achievement of winning all four Majors in a calendar year. However, she was stunned by Vinci in the semis, who used her one-handed slice backhand to devastating effect on the day.

Serena Williams' failure to deal with Roberta Vinci's slice and drop shots in US Open 2015 SF left American bitterly disappointed

Roberta Vinci (left) and Serena Williams (right) before their 2015 US Open semifinal (Source: Getty)

Having won the Australian Open, the French Open, and the Wimbledon Championships in 2015, Serena Williams arrived at the US Open as the favorite for the women's singles title. However, Roberta Vinci, the WTA No. 43 at the time, dashed the American's hopes in the last four, registering a 2-6, 6-4, 6-4 victory aided by her hard-to-read slices and drop shots.

Vinci's ability to mix things up made her incredibly unpredictable and repeatedly caused disruptions in Williams' game. After the match, which is widely regarded as one of the greatest upsets in tennis history, a dejected Williams wrapped up her post-match press conference in just four minutes.

"I don't want to talk about how disappointing this is for me. If you have any other questions I'm open to that," Williams said during the press conference.

Had Williams defeated Vinci and gone on to win the title, she would have become only the fourth woman to complete the Grand Slam after Maureen Connolly, Margaret Court, and Steffi Graf.