Des Smyth made an impressive debut on the Champions Tour. The Q-School medalist, who turned 50 on Wednesday, shot a final-round 66 to share second place with Tom Watson at 11-under-par 205.
Fernandez held the lead after the opening round and was one shot back coming into the final round at TwinEagles Golf Club. He parred his first five holes before a birdie at the par-5 sixth.
The Argentine assumed control with a birdie at the par-4 10th and cruised to the victory as the challenges of his competitors failed to match Fernandez's pace.
He tallied a birdie at the par-5 17th to open a two-shot advantage and left himself with a long birdie chance at the last. Fernandez drained the 60-footer and launched his hat into the air in celebration. The finishing touch left him three shots clear of the field for his first Champions Tour victory since 1999.
'One of the best rounds I've played under the circumstances,' said Fernandez. 'This win means a lot. Before I hit the last putt I thought about my family.'
The 56-year-old pocketed $240,000 for the win.
Smyth debuted in style. The Irishman, who is the oldest player to ever win on the European Tour, bogeyed the par-3 second but responded with back-to-back birdies from the sixth. Smyth added a birdie at the 10th but found trouble again with a 12th.
At the par-5 13th, Smyth holed a 12-foot putt for the first of five consecutive birdies. He had a chance to make it six in a row but his birdie putt at the 18th slipped by left of the cup. Nonetheless, the late run was enough to propel Smyth into a runner-up finish.
'I started slowly and then got going,' said Smyth. 'I was feeling a bit tight all week and it wasn't until today that I loosened up. I really wasn't thinking about winning the tournament.'
Watson also used a late charge to grab his share of second. He birdied three of the last four holes for a round of 69. He remains winless in 84 starts in the state of Florida.
'I was in it the whole time if I wouldn't miss the short putts,' said Watson. 'Florida's just not my state.'
Gil Morgan carded a 4-under 68 to finish four shots off the pace in a tie for fourth. He was joined by Monday qualifier Jay Overton, who fired a course-record 63 on Saturday, and Tom Purtzer at 10-under-par 206.
Hale Irwin, who earned his first of four titles in 2002 at this event, was one shot further back alongside Tom Kite, Leonard Thompson, Tom Jenkins and Jim Thorpe at 9-under-par 207.
Overnight leader Dave Barr, who became the first Canadian to win on the Champions Tour with his victory at last week's Royal Caribbean Golf Classic, struggled with a 3-over 75. He was joined by Larry Nelson in a tie for 12th at 8-under-par 208.