Aussie tennis marathon man Jordan Thompson has continued his impressive year, scoring a three-set win over 13th seed Ugo Humbert at the Cincinatti Masters.
Thompson lost the first set, before bouncing back to secure a 3-6 6-3 7-6 (7-4) over the Frenchman on Tuesday (Wednesday AEST).
The Australian's typically courageous victory set up a second round match against Argentina's Sebastian Baez, winner of six ATP titles.
In other results in Cincinnati, Brandon Nakashima upset No.11 seed Taylor Fritz 6-4 4-6 7-6 (7-4), while 12th seed Ben Shelton edged Reilly Opelka 7-6 (7-3) 7-6 (7-3) in another all-American match-up.
Shelton, Nakashima and Krueger were among five Americans who advanced in the hard-court tune-up for the US Open. Alex Michelsen and Frances Tiafoe also moved on.
The only other seed to advance in men's action was No.14 Lorenzo Musetti, with Italy's Paris Olympics bronze medallist outlasting Chile's Nicolas Jarry 4-6 7-6 (7-5) 7-6 (7-4).
It has been a breakout year for Thompson, who finally clinched his first ATP Tour singles title by upsetting Norwegian Casper Ruud 6-3 7-6 (7-4) to lift the trophy in Los Cabos, Mexico, also winning the doubles with compatriot Max Purcell.
Thompson had a blazing start to the year, beating Spanish legend Rafael Nadal on his way to the Brisbane semi-finals, then reaching consecutive quarters in Dallas and Delray Beach before his Los Cabos run.
The Australian also had an impressive run on British grass, reaching the semi-finals at Queen's before losing to Italy's Lorenzo Musetti, suffering a back injury along the way.
He recovered to play at Wimbledon but exited in the second round, and while he and Purcell made the doubles final they squandered three championship points in losing to Finland's Harri Heliovaara and Briton Henry Patten.