J.J. Spaun became the ninth first-time winner on the PGA Tour this season after holding his nerve in the final round to take victory in the Valero Texas Open.
The American fired a 3-under 69 to finish at 13-under 275, two clear of Matt Jones and Matt Kuchar.
Adam Hadwin, Beau Hossler, Charles Howell and Troy Merritt were a further shot back in tied fourth.
There was a double celebration for Spaun as victory punched his ticket to Augusta National where he'll be playing in his very first Masters next week.
Spaun was one of four co-leaders at the start of play alongside Brandt Snedeker, Dylan Frittelli and Hossler but made a calamitous start when double bogeying the opening hole.
But from there, he was superb.
As others struggled in tough scoring conditions, Spaun played the final 13 holes in 5-under thanks to birdies at 6, 8, 9 (chip-in from 50 feet), 11 and 14.
That run gave him daylight over his rivals and he didn't flinch over the closing holes.
Spaun, who was 31 for 31 inside 10 feet on the weekend, was making his 147th start and became the first player to win after opening his final round with a double bogey since Tiger Woods at the 2008 US Open.
"It's everything you dream of," he said later. "I'm speechless."
Talking about his poor start, he laughed: "I'd rather double the first hole than the last hole."
As for his Masters debut, Spaun said: "It's something you dream of as a kid. I was thinking about it last night. But you've got to do your best to stay in the present. Fortunately I was able to do that."
Difficult week for Masters hopefuls
Rory McIlroy, playing the week before the Masters for the first time since 2014, talked about the importance of getting four rounds under his belt when he addressed the press on Wednesday.
Unfortunately, he managed just two.
Rory's missed cut was far from ideal, his rounds of 72-73 proving two shots too many.
His lacklustre Friday included just a single birdie and there were no real positives in his stats.
At least he has things to work on and will come in fresh.
Defending Texas Open champion Jordan Spieth, who will be going for a second Green Jacket, also had a rather underwhelming week and started with rounds of 72-70-74.
But at least he left on a high note after closing with a bogey-free 5-under 67 to jump 28 places to tied 35th.
Spieth will be delighted with his long game after ranking 1st in Strokes Gained: Tee To Green but he lost over seven strokes to the field on the green which is hard to fathom.
That included a three-putt from three feet and there are certainly some concerns over his short-range putting.
Defending Masters champion Hideki Matsuyama certainly didn't get the warm-up he wanted after pulling out with a neck injury when 1-over for the week after nine holes of his second round.