He did not three-putt a single green and missed only four putts inside 10-feet - three of them coming in the final round.
Playing out of the final threesome, overnight co-leader and World No. 58 Zach Johnson labored to an even-par 36-36=72 in the final round of the Valero Texas Open, dropping four spots to a season-best solo 5th on 13-under 275, four in arrears of overnight co-leader and champion Andrew Landry, who shot 68.
However, he chunked his second shot on the short par-4 17th into a greenside bunker and eventually bogeyed to fall two shots off the pace with just one hole to play. "I thought I was rolling the ball well and felt really good with my irons on the range this morning, so got some stuff to happen".
"I think this is going to give me a lot of confidence to try to do my card for this year", Niemann said. "He was putting great, hitting great shots".
He said his goal of qualifying for the season-ending Tour Championship, restricted to the top 30 players, had not changed.
To win any title on the PGA Tour, bogey avoidance is crucial. O'Hair canned a 55-foot putt from off the edge of the 18th green to secure the co-runner-up finish.
Starting the day tied for the lead with fellow American Zach Johnson, Landy charged out with birdies in his first three holes before parring the final seven to finish with a 17-under total of 271 at TPC San Antonio.
The victory came three months after he lost a playoff to Spaniard Jon Rahm at the CareerBuilder Challenge in California.
"It helps because you get yourself in that situation and you continue to learn", Landry said. After two birdies and two bogeys on the front nine, Johnson caught fire on the back side, sinking 20-foot birdie putts at the par-4 11th and 15th holes and a 17-foot birdie putt at the par-5 14th as well as his closer at the par-5 18th. He'll now have to play his way in again, but he's off to a good start. She notched 21 top-10 finishes before winning.