American Chez Reavie held his nerve at the Travelers Championship to claim his first PGA Tour victory in almost 11 years.
Having started the final round with a six-shot lead, the 37-year-old was just one stroke ahead of major champion Keegan Bradley with two holes to play.
But Reavie followed eight successive pars with a birdie on the 17th, which 2011 US PGA Championship winner Bradley double-bogeyed.
Reavie got through the last with no dramas to clinch his second PGA title and first since the Canadian Open in July 2008.
Reavie, whose sole blemish for the day came on the par-three eighth, finished with a par for a one-under 69 that gave him a four-shot victory in Connecticut.
Bradley had made a late surge with four birdies in six holes on the back nine but his slip up on the 17th saw him end in a tie for second alongside fellow American Zack Sucher.
Sucher had led after the second round but fell away dramatically when he dropped five shots in three holes on the back nine on Saturday.
He responded on the back nine on Sunday as he recorded five birdies to end the tournament on 13 under.
Seamus Power's week ended on a sour note as a five-over 75 saw him slip 25 places to a tie for 66th. Power had three bogeys and a double on the par-five 13th and failed to record a birdie.
The final leaderboard @TravelersChamp:— PGA TOUR (@PGATOUR) June 23, 2019
1. Chez Reavie, -17
T2. @ZackSucherPGA, -13
T2. @Keegan_Bradley, -13
4. @VaughnTaylorPGA, -12
T5. @Paul_Casey, -11
T5. @JoacoNiemann, -11
T5. @KevinTway, -11
Full leaderboard: https://t.co/2kFgCQQ8n7 pic.twitter.com/vH3TuqNVWr