Roger Federer has breezed through the 2019 French Open so far, but a tough test awaits in Tuesday’s quarterfinals versus Stan Wawrinka. The match begins at 8 a.m. ET from Roland Garros in Paris. Federer, the third seed, whipped Leonardo Mayer 6-2, 6-3, 6-3 on Sunday and his four matches have lasted 7 hours, 10 minutes total. Wawrinka, the 24th seed, is coming off a 5-hour, 9-minute, five-set marathon win over Stefanos Tsitsipas. Federer and Wawrinka also met in the 2015 French Open quarterfinals, Wawrinka winning in straight sets en route to the championship. Bookmakers list Federer as a -290 favorite (risk $290 to win $100) in the latest Federer vs. Wawrinka odds, with Wawrinka getting +235 (risk $100 to win $235) as the underdog in the latest 2019 French Open odds. The over-under on total games is 17.5, and Federer is favored by 4.5 on the game spread — among a slew of wagering possibilities being offered on this intriguing match. Before you make any Federer vs. Wawrinka picks or 2019 French Open predictions, see what famed tennis expert Sean Calvert picked.

The internationally-acclaimed tennis journalist has been cashing consistently for six years and just took down a huge score on Dominic Thiem winning Indian Wells at 80-1. Calvert is known for making legendary calls like Wawrinka to win the 2014 Australian Open at 60-1, and Jack Sock to win the 2017 Paris Masters at 80-1.

More importantly, Calvert specializes in Grand Slam events. In the 2017 French Open, for instance, $100 bettors who tailed him returned more than $1,600. This is the same expert who, at last year’s Wimbledon, called Federer’s stunning quarterfinal upset loss to Kevin Anderson.

Now, Calvert has broken down all the Federer vs. Wawrinka odds and released a stunning best bet that pays more than 4-to-1. He’s sharing it over at SportsLine.

Calvert knows Federer, who won his only French Open crown a decade ago, “has made his usual serene progress to the quarterfinal stage, barely breaking a sweat in a pretty easy draw and spending around seven hours in total on the court, compared to Stan’s 12 and a half.”

Federer is 25-3 all-time versus Wawrinka. But the younger Swiss actually has beaten Federer in two of their past three matchups on clay. And the unsettled weather forecast — rain and thunderstorms are predicted Tuesday — could force a delay that will benefit Wawrinka.

“Certainly on the form that Wawrinka showed against Cristian Garin and Grigor Dimitrov, you’d give him a decent shot against an almost 38-year-old Federer who hasn’t played more than three sets in a match on clay since 2015,” Calvert told SportsLine, adding:

“The betting odds on Federer have the fatigue factor for Wawrinka built in.”

Given that backdrop, Calvert is all-in on a best bet that would pay out at well over 4-1. You need to see his specific recommendation at SportsLine before locking in your picks.

So who wins Federer vs. Wawrinka? And what best bet should you make for a payout of well over 4-1? Visit SportsLine now to see Sean Calvert’s detailed French Open quarterfinal picks, all from the international tennis expert who just called Dominic Thiem winning Indian Wells at 80-1.