Andy Roddick endured a night to forget at the SAP Open in San Jose, losing to Denis Istomin at the quarter-final stage.
The former world number one, trying to find his form again after an injury-ravaged start to the season, bowed out 6-2 6-4.
He was clearly rattled, too, hitting balls out of the court, breaking his rackets, arguing with the umpire and shouting at his coaching box.
His demeanour was somewhat different to that of the latest American star, teenager Ryan Harrison.
He cruised through his last-eight tie with Dimitar Kutrovsky, winning 6-1 6-4 to move to within two wins of what would be a first Tour title.
He needs to beat the defending champion to reach the final, though, with big-serving Milos Raonic next having got the better of Kevin Anderson 7-5 7-6 (7/3).
In the day's final match, Julien Benneteau came from behind to defeat Steve Darvis 3-6 6-1 6-2, setting up a meeting with Istomin in the semi-finals.