Toms fired a final round 5-under-par 66 to force a playoff with Weir, who birdied four of his final five holes in regulation to finish the tournament at 13-under-par. Frank Lickliter finished third, two shots off the lead. 54-hole leader Bradley Hughes tied for 5th following a final-round 1-over-par 72.
Last year, Weir took the outright lead into the final round at Kingsmill, but carded a Sunday 70 to miss out on a playoff, which was eventually won by Notah Begay III, by one shot.
This year, the left-handed Canadian started the final round four shots back of Hughes. After making the turn in 2-under-par 34, Weir birdied the 12th, 14th, 15th, 16th and 18th holes for an inward half of 5-under-par 30. Weir's overall 64 gave him the clubhouse-lead at 13-under-par.
Toms started the day two off the lead, but moved to the top of the leaderboard with a birdie 2 at the par-3 13th. Toms then took sole possession of the lead at 14-under-par with another birdie at the par-5 15th. However, he gave the shot back on the next hole, when he failed to get up and down from off the green at the par-4 16th.
Toms wasn't able to birdie either of the final two holes in regulation, but he did convert a pair of crucial par saves.
Tied at 13-under, Toms and Weir went back to the 18th tee. Toms found the fairway. Weir flirted with danger in the left-hand rough. From the fairway, Toms was able to place his approach shot onto the green, though his ball finished 45 feet and a double breaker away from the hole.
Weir was unable to hack his second shot onto the putting surface. From below the green, the 1999 Air Canada champion chipped up to 10 feet, but was unable to convert the par save.
Faced with a difficult birdie putt, Toms was able to coax his first stroke to within five feet of the cup. Following Weir's miss, Toms calmly knocked in his par putt for his first title of the season.
'Just like Michelob Light, it tastes pretty good,' Toms said. 'But, yeah, it is very satisfying to win here. Hopefully, if I can finish out strong, maybe I can improve on my position I had last year.'
Last year, Toms finished 10th in earnings. With his win this week, and the $540,000 first-place check that goes along with it, Toms moves from 30th on the money list to 16th. The top 30 prior to the Tour Championship earn a birth into the season's final event.
This is Toms' first victory since the 1999 Buick Challenge. Last week, he tried to defend his title, but missed the cut at Callaway Gardens.
Toms' win was a bit of a surprise, not because of who he was, but because of how he felt. Friday, Toms considered walking off the course due to a bad back. Instead, he took a 'handful of Advil' from Paul Azinger and kept going.
'Saturday morning on the range Azinger came up to me and he said, `Man I didn't realize you were 30th on the money list. You need to suck it up out there,' I said yes, and I did. The week work out great.'
David Duval knows a thing or two about back pain. Last week's Buick Challenge winner was commissioned to the couch for 10 week following the British Open.
This week, Duval was in contention through 13 holes, but, showing his back isn't completely healed, the two-time Michelob champion bogeyed his final five holes on Sunday to fall into a tie for 19th.
Lickliter birdied two of his first three holes to get to 11-under, but could get no lower. Seeking his first career victory, Lickliter parred the final six holes to finish in solo third place.
Hughes began the day with a one-shot lead, but bogeyed two of his first three holes to lose his edge. The 33-year-old Australian managed two birdies and an eagle in the final round, but also carded five bogeys.
Still, Hughes' tie for 5th was good enough for a $105,375 paycheck. That moves the Aussie from 126th on the 2000 money list into 96th place.
'I guess I'll have to tell the officials to tear-up my entry form for Q-School,' Hughes said with a smile.