NEW YORK, Sept 3 (Reuters) - Big-hitting former champion Juan Martin del Potro will battle baseline specialist Dominic Thiem when the pair meet on the Grandstand in the fourth round of the U.S. Open on Monday.
Del Potro has defeated the 23-year-old Austrian in their previous two meetings, including a win at Flushing Meadows last year when Thiem was forced to retire in the second set due to a right knee injury.
Thiem has been improving as the tournament has gone along and beat Frenchman Adrian Mannarino in straight sets to advance to the fourth round in a power-packed end of the draw.
The 6-foot 6-inch Del Potro, meanwhile, has unleashed the big serve and punishing groundstrokes that won him the title in 2009 through his first three matches.
The 28-year-old has yet to drop a set while dispatching Henri Laaksonen, Adrian Menendez-Maceiras and Roberto Bautista Agut.
The winner will meet either five-time champion Roger Federer or German Philipp Kohlschreiber in the quarter-finals. (Reporting by Rory Carroll; Editing by Ken Ferris)