World number 161 Rajeev Ram knocked out the 18th-ranked John Isner in Newport, continuing his solid record at the event.
Rajeev Ram won his first ATP World Tour match of the season, scalping top seed John Isner at the Hall of Fame Tennis Championships on Tuesday.
The 2009 champion ousted two-time winner Isner 6-7 (5-7) 6-3 7-6 (10-8) in one hour and 55 minutes on the US grass courts, the American delighted to keep up his good record at the ATP 250 event.
Ram's career singles win-loss record now sits at 37-67, but at Newport he has a much more appealing 12-5 ledger.
"It's sort of suited to old-school tennis, and I feel like I can play that pretty well with almost anyone around," Ram said, as reported by ATPWorldTour.com.
"It came down to a couple points... I was able to get him today."
Also bowing out at the first time of asking was eighth seed Tim Smyczek, with qualifier Jan Hernych completing a 6-3 6-4 victory.
Dustin Brown, fresh from his Wimbledon heroics, also progressed.
The German defeated Rafael Nadal at SW19, and continued his grass-court form with a 7-6 (7-4) 6-3 win over qualifier Adrien Bossel.
Fourth seed Jack Sock thrashed Radek Stepanek 6-2 6-0, while Sam Querrey - seeded sixth - edged out qualifier Matthew Ebden 7-6 (7-3) 7-6 (7-1).
Set to resume at one-set all on Wednesday are wildcard Tommy Haas and fifth seed Adrian Mannarino.
German veteran Haas won the first set 7-6 (7-5), but Mannarino forced a deciding set with a 7-6 (7-1) win in the second.
Malek Jaziri downed qualifier Ante Pavic 6-2 4-6 7-5, Yuichi Sugita knocked out local hope Ryan Harrison 6-1 5-7 6-3 and Lukas Lacko fought past Niels Desein 6-3 3-6 6-2.