Named to the World Golf Hall of Fame on Wednesday, Singh capped off a big week by tapping in an 18-inch putt on the first playoff hole to claim his second title of the season and 26th of his career.
The victory was not enough to allow the Fijian to reclaim the world number one spot from Tiger Woods but will leave only fractions separating the two great rivals when the new rankings are released on Monday.
The 7,508-yard Redstone Golf Club and its wide open fairways held mouth-watering appeal to the PGA Tour's heavy hitters and Daly and Singh, two of golf's biggest swingers, took full advantage.
Singh flexed his muscles in the opening round with a course record-tying 64 but played far less spectacular golf the rest of the week.
The smooth-swinging Fijian, however, did little wrong over the final three rounds carding just three bogeys to stay near or top of the leaderboard to finish on 13-under 275.
Singh began the day tied for the lead with Australia's Gavin Coles but was slow to make a move as he stalled on 11-under with pars on his first 13 holes.
Back-to-back birdies on 14 and 15 vaulted Singh back into the championship chase and left him with a chance to clinch the title with a six-foot birdie putt on 18.
But Singh's shot drifted just wide of the cup and he headed back to the 18th
Fan favourite Daly launched a late charge with birdies on three of his final four holes for a five-under 67.
The hugely popular American capped off his round with a nervy 10-foot birdie putt on the last that brought a huge fist pump from Daly and an even bigger ovation from the gallery.
Daly's hopes of victory disappeared quickly, however, when his tee shot on the first playoff hole found the water while Singh continued to play error-free golf.
Spain's Jose Maria Olazabal continued to enjoy his rich early season form, signing for a final round two-under 70 to finish alone in third with 11-under 277.
Britain's Darren Clarke, who suffered a final round collapse at last week's Heritage Classic, rebounded with a superb finish in Houston firing a five-under 67 to join compatriot Greg Owen at 10-under 278.
Coles, ranked 388th in the world and without a top 10 PGA Tour finish, had shared the second and third round lead but the gritty Australian saw his hopes of a first title vanish with a double-bogey on the 11th that sent him tumbling down the leaderboard into a tie for seventh at eight-under 280.