Volkswacht Bodensee - Shelton fends off Damm at Washington as veteran Venus ousted

Shelton struggled when the match resumed after a delay of more than two hours, but came through 6-4, 4-6, 6-4 against his American compatriot in his first hardcourt match ahead of the US Open.

"Happy that I was mentally stable and tough enough to get through that match," said the 23-year-old left-hander, who is seeking his fourth ATP tour title of the year after triumphing in Dallas, Munich and Stuttgart.

Shelton, the world number eight, next faces French left-hander Ugo Humbert for a quarter-final berth.

Shelton led 6-4, 4-3 when play was halted, then saw Damm hold, break on a long forehand and hold again to force a third set.

After trading breaks in the third and fourth games, Shelton broke on a backhand crosscourt volley winner at 5-4 to settle matters after 2hr 9min.

"A tricky match to be in command, in the driver's seat of the match and feel like playing really well, then have a rain delay and the guy come out on fire," Shelton said.

"That was tough to swallow losing that second set the way I did, but happy with the way I fought."

Seven-time Grand Slam singles champion Williams, 46, suffered her 12th consecutive defeat, 6-3, 6-3 to Austria's Anastasia Potapova in a first-round match.

Williams has not won a WTA match since a first-round triumph over American Peyton Stearns in Washington last year.

Cruz Hewitt, the 17-year-old son of former world number one Lleyton Hewitt, captured his first ATP Tour victory.

The Aussie teen, ranked 612th in the world, ousted fellow qualifier Marcos Giron of the United States 6-3, 6-4 in 74 minutes in his ATP main draw debut.

Among his father's 30 career ATP titles was the 2004 Washington crown.

"It's a pretty special moment," Hewitt said.

"Seeing my dad play this tournament and to get my first tour win, it feels really cool."

Hewitt will next play the winner of a match postponed to Wednesday between Greek Stefanos Tsitsipas and Australian newlywed Alex de Minaur, the top seed and defending champion.

Alexandra Eala, who made global headlines when beating Iga Swiatek at Wimbledon and becoming the first Philippines player to reach the last 16 of a Grand Slam, rallied to defeat China's Zheng Qinwen 4-6, 6-4, 6-1 after 2hr 26min.

Eala, 21, will face defending champion and seventh seed Leylah Fernandez of Canada on Wednesday for a place in the last eight.

G.Haefliger--VB