'I love Panama. This is a really cool place to get your first win,' said Walker. 'The crowds were great. Having them cheer for you is awesome.'
Tom Scherrer struggled to a 2-over 72 but held on to second place at 2-under-par 278. Ryan Armour posted an even-par 70 to finish as the final player under par at minus-1.
The course played to a stroke average of 72.812 for the four rounds.
Walker opened the day at Panama Golf Club with a two-stroke lead. He got going quickly with a birdie at the par-4 second.
He faltered to a bogey at the next, but immediately responded with a birdie at the fourth. The 25-year-old settled down to par the remaining five holes on the front side.
Around the turn, he stayed steady with three more pars. The Baylor University product dropped a shot at the par-3 13th for the second straight round, but his lead was still four shots. Walker capped his first Nationwide Tour win with a birdie at the par-4 16th.
'The putt on No. 16 iced it a little bit,' Walker said. 'When it went in is when I felt like it was over.'
The victory for Walker came in his 32nd start on tour.
'My goals are still the same,' said Walker, who earned $90,000 for the win. 'Obviously you want to win three times and finish inside the top-20 and this gives me a good start on those goals.'
Scherrer was the lone player that had a chance to threaten Walker's lead, but he stumbled out of the gate with a bogey at the first. He did come back with a birdie on No. 5, but trailed Walker by three strokes at the time.
The two-time winner on the Nationwide Tour dropped another shot at the sixth. He fell to 2 under with a bogey at the par-4 10th and parred in to finish alone in second.
'I had a few chances today but I just couldn't get close,' said Scherrer. 'I didn't make any putts over the weekend. He went out and did what he had to do.'
Steve Ford and Chris Sessler each carded even-par rounds of 70 to finish the event at 1-over-par 281. They were joined there by Jason Caron and Paul Gow, who each shot 73. Greg Bruckner, who shared the lead after the first round, shot 3-over 75 to finish alone in eighth at plus-2.
Chris Zambri, Curt Byrum and Jeff Klauk shared ninth place at 3-over-par 284. Matt Bettencourt, Jeff Freeman, Rafael Gomez, Jon Mills and Jim Rutledge were one stroke further back at plus-4.