Fifth-seeded Kevin Anderson outlasted Grigor 6, 7-6 (7-5), 7-6 (7-3) in first-round action at the SAP Open on Monday.

Dimitrov cruised in the first set before losing a second-set tiebreaker on an Anderson ace. The deciding set also went the distance, and the South African earned the first mini-break at 3-2 before finishing off the two-hour, 27- minute affair.

Germany's Tobias Kamke defeated Izak Van Der Merwe of South Africa in straight sets, 6-3, 6-3, in Monday's only other first round match. The remainder of the opening round will conclude Tuesday.

The top four seeds -- Gael Monfils Andy Roddick, Milos Raonic and Randy Stepanek -- all received byes into the second round.

Raonic is the defending SAP Open champion while Roddick is a three-time winner of this event. Monfils is making his second tournament appearance and reached the semifinals a year ago, falling to Raonic. Stepanek won the tournament in 2009.