REUTERS: Philipp Kohlschreiber upset second seed Marin Cilic 6-4 6-4 to advance to the fourth round in the BNP Paribas Open at Indian Wells on Tuesday.
Cilic's booming serve lacked its usual accuracy and Germany's Kohlschreiber was able to control long rallies, pushing the towering Croatian around the court with pinpoint groundstrokes en route to a quick victory.
Cilic, runner-up at this year's Australian Open, only managed to get 51 percent of his first serves in play and was unable to convert any of his four break-point opportunities.
It is the third time that Kohlschreiber has reached the fourth round at the tournament in the California desert and his seventh victory over Cilic in 11 career meetings.
The 31st seed will next face Frenchman Pierre-Hugues Herbert, who advanced after Gael Monfils was forced to retire from their match due to back pain.
Elsewhere six seed Juan Martin del Potro fended off a lively challenge from veteran Spaniard David Ferrer 6-4 7-6(3), who battled gamely but was ultimately worn down by del Potro's big serve and punishing forehand.
The win sets up an all-Argentinian fourth round battle between del Potro and countryman Leonardo Mayer, who earlier cruised to a 6-4 6-1 victory over Japan's Taro Daniel.
(Reporting by Rory Carroll; Editing by Toby Davis)