Mitchellville, MD (My Sportsbook) - Mathias Gronberg posted rounds of 67 and 65 on Sunday to earn a six-stroke win at the Melwood Prince George's County Open.

Gronberg closed out his first Nationwide Tour victory at 19-under-par 269. He bettered the tournament scoring record by one stroke. Paul Claxton set the old record of 270 in 2007.

"I came off with a couple of birdies in the first round this morning. That kind of relaxed me and I felt like it was my day and I just kept playing great golf," said Gronberg, who collected $121,500 for the win.

Robert Damron (67) and Justin Bolli (70) shared second place at 13-under-par 275. Esteban Toledo took fourth at minus-12 after a final-round, six-under 66.

Both the third and fourth rounds were completed on Sunday after a long weather delay pushed the completion of the first round to Saturday. The second round was also completed Saturday, then the 68 players that made the cut played the final 36 holes on Sunday.

Gronberg, who was the medalist at PGA Tour Q-School in 2003, had three birdies and an eagle in the third round as he took the lead into the final round.

The Swede continued his strong play on the second 18. He birdied the third, then ran off three consecutive birdies from the sixth to jump to 16-under.

Gronberg sank a five-footer for birdie at 10, then tapped in a two-foot birdie effort on the 12th to move to 18-under. He collected his last birdie on the 17th, where he converted from 10-feet out. Gronberg parred the last to complete the final 36 holes bogey-free.

"I thought I had a pretty good lead. I didn't want to look at the leaderboard. I just wanted to try to focus on not making bogeys and making a couple birdies," said Gronberg, who didn't know he had such a big lead. "I'm very proud of the way I played the back nine."

Damron moved from a share of 10th into a tie for second with a six-birdie, one-bogey round. Bolli had three bogeys in his first 10 holes, but birdied five of the last seven to share second place.

Oskar Bergman, who shared the lead with Gronberg entering the final round, stumbled to a one-over 73 to share fifth place at 11-under-par 277. He was joined there by Tom Scherrer (72). David Peoples, Cameron Percy and Jeff Curl shared seventh place at minus-10.