'It's a dream come true to win on the PGA Tour,' said Hensby. 'And to win obviously a PGA Tour event in Illinois is pretty special, too, because this is kind of where I got my career started, in the United States, in Illinois.'
Hensby and Morgan finished regulation tied atop the leaderboard at 16-under- par 268. With a thunderstorm to the west that had been looming throughout the afternoon, the duo began the extra session at the par-4 18th and both players had reached the green before play was halted.
The delay was the second of the day, as the start of the final round was pushed back over an hour due to fog at the TPC at Deere Run.
When conditions improved enough for the players to return to the course, Morgan stared down his birdie try from outwards of 80 feet. Morgan ran his putt past the hole and watched as the ball stopped 9 feet from the cup on the edge of the green.
Hensby was on the green within 22 feet of the hole. His birdie putt missed just left and he tapped in for par. With the pressure on, Morgan converted his par try and exploded with emotion just as he had all day.
The players headed to the par-3 16th and Hensby played his tee shot first, landing his ball safely on the putting surfaced. Morgan meanwhile launched his tee shot and waved as it carried over the green into the hazard.
Morgan, unable to ground his club in the hazard or take a practice swing, struggled to find his balance against a slope. He punched his second shot out of the mess and the crowd groaned as it scooted across the green into a bunker.
Morgan was up again and hit out of the sand, narrowly missing for par. Hensby, playing next, needed two putts to win and did just that, tapping in for par and his maiden PGA Tour title. Hensby also earned a spot in the British Open with the win, but has opted not to go.
'It's a pretty easy decision really,' said Hensby. 'I just don't feel like I could go over there and play my best golf, travelling tomorrow. I've traveled all over the world and I know it's just not that easy to climatize yourself, so it was really a no-brainer.'
Hensby was four shots behind Jose Coceres to start the day, but made up that ground on the front nine. He birdied each of his first two holes and ran off three consecutive birdies starting at the par-4 sixth to reach minus-16.
The Australian recovered with a birdie at the par-4 11th and parred his way in for a round of 66.
Morgan took a different route. He stood five shots back heading into the final round and picked up a lone birdie on the front nine.
The Englishman caught fire around the turn, however, starting with a birdie at the par-5 10th. Morgan then birdied three in a row from the 14th and closed with a birdie at the last to match Hensby at 16 under and earn a spot in the playoff.
'I'm pretty stuck for words at the moment, even though I just lost in a playoff,' said Morgan. 'But I've very, very proud of myself, very proud of everybody that supported me actually, just absolutely unbelievable feeling to have that much support with the fans.'
Coceres was unable to capitalize on his lead. The Argentine, who was seeking his third career victory on the PGA Tour, managed a round of 71 to finish alone in third place at 15-under-par 269.
Last year's champion Vijay Singh was one shot further back after a round of 67. Singh was joined by Greg Chalmers, who had an ace on the seventh hole, Joel Kribel and Steve Stricker in a tie for fourth at 14-under-par 270.
John Rollins, who also aced the seventh on Sunday, followed at 13-under-par 271 along with Jeff Sluman and Stewart Cink.