Roddick rolls into quarterfinals at Delray Beach

Andy Roddick earned a straight-set victory on Thursday to advance to the quarterfinals of the Delray Beach International Tennis Championships.

The fourth-seeded American reeled off six aces and converted all three of his break chances against Uzbekistan's Denis Istomin en route to a 6-4, 7-5 victory on the hardcourts at Delray Beach Stadium and Tennis Center.

The former No. 1 Roddick, who is currently ranked 30th in the world, was upset by Istomin in San Jose just two weeks ago, but saved 4-of-5 break chances to overcome seven aces by Istomin to advance.

Seventh-seeded South African slugger Kevin Anderson made sure Delray Beach stalwart Xavier Malisse would not reach a sixth final here this year, as Anderson posted a 6-3, 3-6, 6-3 decision on Day 4. The five-time finalist Malisse was the champion here in 2005 and 2007 and runner-up in 1999, 2001 and 2006.

Meanwhile, fifth-seeded German Philipp Kohlschreiber clobbered Croatian Ivan Dodig 6-2, 6-2 and Israeli Dudi Sela defeated Finnish fellow non-seed Jarkko Nieminen 6-4, 6-4. Kohlschreiber will face Sela on Friday.

The 2012 Delray Beach winner will collect $75,780.