Frost joined 2011 winner Nick Price as the only golfers to lead wire to wire in the event's 19 years. It was his fourth career Champions Tour victory and first since last year's AT&T Championship in San Antonio.
"I felt as good as I did the first two days," Frost said. "I really enjoyed the tussle with Freddy (Couples) out there."
In four events this season, Frost hasn't finished out of the top 10, posting ties for ninth, fifth and losing in a playoff to John Cook in Hawaii in the season-opening Mitsubishi Electric Championship.
"I've been playing really, really consistently and haven't had any of those ups and downs," Frost said. "I know they will come, but right now I am playing well."
Couples, the 2010 champion, began the day a stroke behind Frost and tied him with a birdie on the first hole. That was the last time Frost would relinquish the lead. He birdied the second and third holes to build a two-shot advantage and his lead never went lower than one the rest of the round.
"Freddy was the one they were rooting for," Frost said of playing with Couples. "Fortunately, my putter was a little hotter than his was. There was too much work for him. I wasn't really hitting bad shots."
After making a birdie on No. 10 Couples had a chance to tie Frost again, but made a bogey two holes later and never recovered. Couples battled back pain for most of the day, especially on the back nine. After hitting an approach shot on No. 16 Couples dropped his club and bent over in obvious discomfort.
"I was feeling good, but then I got really, really stiff," Couples said. "I hit a lot of bad wedges. I hit a bad wedge on 6 and 7 and 16. I was kind of flinching at it. They weren't very good swings either."
Jay Haas, the 2007 winner, finished tied for third with Peter Senior at 11 under. Tom Watson finished fifth another stroke back and Champions Tour rookies Rocco Mediate and Esteban Toledo tied for sixth at 9 under.