The three-time major champion held seven match points against Dominik Koepfer, but couldn't seal the deal.

The left-hander prevailed after three hours and one minute on Monday evening to hand the 2016 champion his first loss from match point up in nine years.

With no Serena in New York, Stephens finds herself as a senior member of the U.S. women’s contingent. If that doesn’t make her feel her age, facing the 17-year-old Gauff surely will.

The German has played eight sets against the star server, and has won every single one.

The 20-time Grand Slam champion had completed a four-set victory over Dominik Koepfer at 12:43 A.M. in Paris the previous night.

"For me these are all stepping stones, right, to something that is really important to me. It's the season, and it's the comeback. I need matches like these, you know," said Federer.

Who should be favored: the defending champion, or a player who leads the head to head 2-0?

The Russian was ranked No. 253 on the ATP rankings at this time last year, while the Italian teenager was No. 284.

Look for Dominik Koepfer to keep things close against Zverev. In Dubai, Aslan Karatsev is poised to capture his first ATP singles title.