Arron Oberholser, who won last week's Utah Classic, fired a 66 to finish at 15-under-par 273 alongside Tag Ridings, Patrick Moore, Jeff Freeman and Marco Dawson.
'I had fun but this one was hard-fought,' said Gore. 'Today was a grinding day. The kind where you get your shoes dirty and go do it.'
Gore came into the final round with a two-shot lead at Shadow Hills Country Club and played steadily on the front nine with a lone birdie at the par-3 fourth.
'I was nervous standing on the first tee, no doubt. If you're not nervous, something's wrong with you,' said Gore. 'I felt good all week and thought the only person who could beat me was me.'
The 28-year-old was playing at his own pace but he picked up steam with a pair of birdies starting at the 10th to reach 20-under.
Gore found trouble at the par-3 12th, however, when his tee shot found a front bunker. Gore hit out and two-putted for his first bogey of the day. He faltered again with a bogey at the 17th but his lead was never in doubt.
'I missed it in some right spots,' said the former All-American from Pepperdine University. 'You have to play well badly. I did that today. It added a little grit to it.'
Gore, who had posted two top-10 finishes earlier in the year, earned his second career victory on the Buy.Com Tour. His first came at the 2000 New Mexico Classic.
Gore pocketed $76,500 for the win.
John Restino collected four birdies and no bogeys for a round of 68 to finish alone in seventh at 14-under-par 274. He was followed by Omar Uresti, who was one shot further back at 13-under-par 275.
Ryuji Imada, who was two shots off the lead after three rounds, struggled with a final-round 75. Imada finished at 12-under-par 276 along with Eric Johnson, Jason Buha, Darron Stiles, Fran Quinn, Kevin Wentworth, Tjaart van der Walt and Brent Winston.
Ted Purdy, who held the 36-hole lead, finished seven shots off the pace in a group at 11-under-par 277.
Final results from the Oregon Classic