Omar Uresti shot a 9-under 63 to join Danny Briggs at 12-under-par 204. Todd Hamilton, Kris Cox and Danny Ellis were one shot further back at 11- under-par 205.
Play is split over the Panther Lake and Crooked Cat courses at Orange County National. The tournament is 108 holes, with a cut after the first 72, and the top-30 and ties after Monday's final round, earn their PGA Tour cards for the 2004 campaign.
Chopra played the back nine first at Crooked Cat and tallied his first birdie of the day at the par-4 11th. He then added back-to-back birdies starting at the par-4 16th and kept on rolling with two consecutive birdies from the par-4 third.
The Swede, who narrowly missed a PGA Tour card by finishing just outside the top-20 on the Nationwide Tour money list in 2003, added a birdie at the par-3 sixth and picked up another birdie at the par-3 eighth to secure his share of first.
'Today was a great day for me,' said Chopra. 'Finally my iron play picked up, especially on the par-3s. I've had two bogey-free rounds this week which is pretty good. You just try to avoid bogeys out here.'
Chopra's countryman Gronberg also started at No. 10 on the Crooked Cat layout and ran off a pair of birdies starting at the 16th.
He continued his steady play on the inward half with birdies at Nos. 1,3 and 5 en route to a round of 67.
'I didn't play that good today but I still managed to score well,' said Gronberg. 'I hope I hit better drives tomorrow.'
Uresti ran off 10 birdies and a bogey at Crooked Cat to post the low round of the tournament and match the course record.
'It was a good solid day,' said Uresti. 'I actually got off to a rough start with a bogey on my first hole. But after that I got on a tear, hit some good shots and from there I was cruising.'
David Branshaw posted a 5-under 67 to finish alone in eighth place at 10-under-par 206.
Kevin Na, Ken Duke, Brian Bateman, Jon Mills, Michael Allen and John Riegger were one shot further back at 9-under-par 207.
Charles Warren joined Olin Browne, Scott Hend, Bradley Hughes, Wes Short and Dan Olsen at 8-under-par 208.