Nathan Green shot a 64 to finish four shots off the pace in a tie for second with Franklin Langham at 26-under-par 262. James Driscoll and Ryuji Imada were one shot further back at 25-under-par 263.
Chopra, who has status on the PGA Tour, posted his third 65 of the tournament Sunday at The Dominion Club. He shattered the low 72-hole score on the Nationwide Tour by four strokes and his 258 total matched Chris Smith's mark set at the 1997 Omaha Classic.
'I'm very familiar with the golf course and I love it,' said Chopra. 'The kind of scores I was shooting, 65 was my worst round, it's unbelievable.'
The Swede took a two-shot lead over Langham into the final round and quickly dropped his second shot to the par-5 second inside 10 feet for an eagle. Chopra followed that up with a birdie at the par-3 third after his tee shot stopped within 12 feet of the cup.
Chopra knocked his tee ball to 6 feet for a birdie at the par-3 ninth and drained an 8-foot putt for a birdie at the par-5 12th to reach 28 under.
The 30-year-old kept on rolling and hit his approach to 13 feet for a birdie at the 16th. Chopra then closed the tournament in style with a birdie at the last.
'It's been an amazing week,' said Chopra. 'This has just been huge.'
With two wins this season on the Nationwide Tour, Chopra is very close to wrapping up his playing status on the PGA Tour for next year and does have some freedom when it comes to the remainder of 2004.
'I'm just going to enjoy it for now,' said Chopra. 'I'm probably not going to play everything out here and PGA Tour at the same time, but if I feel like playing and I don't want to sit at home on the couch and just watch TV, I'll play.
'I do feel great out here. I feel like I know the golf courses, I know the players. It's like coming home.'
Green, who shot a 62 in the opening round, collected four birdies on the front side to make the turn at 22 under. The Australian added four more birdies on the inward half for his share of second.
Langham, who played alongside Chopra in the final group on Sunday, mixed two birdies and two bogeys on the front side, but ran off five birdies on the back nine for a round of 67.
Nationwide Tour money leader Jimmy Walker posted a 65 to finish alone in sixth place at 24-under-par 264. Johnson Wagner and Bryant MacKellar followed at 22- under-par 266.