MONTE CARLO, Monaco, April 16 (UPI) -- Grigor Dimitrov posted a straight-set upset victory Tuesday in second-round play at the Monte Carlo Rolex Masters tennis tournament.
Dimitrov stopped eighth-seeded Janko Tipsarevic 7-6 (7-3), 6-1. He had five aces and lost only 12 points in nine service games. He did drop a service game in the first set but took nearly two-thirds of the points overall in winning the second set and closing out the match.
The other second-round matches Tuesday played to form with seeded players advancing.
Fifth-seeded Juan Martin del Potro rallied for a 1-6, 6-4,6-3 win over Alexandr Dolgopolov. After going 0-for-3 in break opportunities in the first set, del Potro finished off all five of his chances in the next two sets.
No. 6-seeded Jo-Wilfried Tsonga got by Nikolay Davydenko 7-6 (7-3), 6-2 while Richard Gasquet, the seventh seed, topped Benoit Paire 6-1, 3-6, 6-1 and 16th-seeded Philipp Kohlschreiber edged Pablo Andujar 6-2, 2-6, 7-6 (7-3) in second-round action.
The first round wrapped up Tuesday with Ernests Gulbis beating John Isner 4-6, 6-2, 6-3. Isner, coming off a win Sunday in Houston at the U.S. Clay Court Championship, suffered an uncharacteristic four breaks at the hands of Gulbis.
No. 10-seeded Nicolas Almagro advanced to the second round with a 2-6, 6-1, 6-3 decision over David Goffin, while 13th-seeded Stanislas Wawrinka beat Denis Istomin 6-3, 7-5 and 14th-seeded Juan Monaco defeated Martin Klizan 6-4, 6-0 in their first-round matched.