MOBILE, Ala. -- Jennifer Johnson started using what she called a "spaceship" putter this week, and it launched her into a higher orbit in the LPGA.
Johnson shot her second straight round of 7-under 65 to capture her first tour victory at the Mobile Bay LPGA Classic on Sunday.
Johnson's four-day total of 21-under-par 267 on Magnolia Grove's Crossing Course was a tournament record and gave her a one-stroke victory over Jessica Korda and Pornanong Phatlum.
Johnson had one top-10 finish in her LPGA career before Sunday -- an eighth-place showing in another Alabama tournament, the 2011 Navistar LPGA Classic in Prattville.
"I was putting with kind of a traditional blade-style putter," Johnson said, "and I went to a Futura, which looks like a spaceship -- I call it the spaceship -- and it's just flowing better with my stroke, more like a pendulum, and it just feels good.
"Before this week, I had experimented with more of a forward press, and it just doesn't fit my style of putting. So I worked with my coach on making it kind of more like a pendulum, and this new putter that I put in play really emphasizes that, and so I can stroke it easier and I don't have to work as hard to get it like rolling on line.
"The putter has kind of been the missing link because I'm hitting the ball so well. And when they go in, it really helps score."
Johnson birdied four of the final six holes on Sunday to win a shootout in which nine players bettered the tournament record of 17-under-par.
"It was pretty intense for me," Johnson said. "I was telling my caddie, 'Man, I haven't seen that much tension on a golf course in a while.' And he's telling me, 'What? What's intense?' So he was trying to keep me loose, crack some jokes. ... It was like birdies after birdies, and you had to keep making them to keep up.
"I'm a little shocked. I didn't even realize I shot 65. The whole back nine was kind of like a -- I don't know. I don't know what was happening."
Third-round leader Chella Choi had one bogey in the first two rounds. But she turned the back nine into a free-for-all by bogeying back-to-back par-4s on the 11th and 12th holes. That dropped her to 18-under.
Johnson was the first to get to 19-under down the stretch. She birdied from 12 feet on the par-3 14th hole, which played the toughest on the course on Sunday.
Choi got it back together to join her at 19-under with a 15-foot birdie putt on 13.
Phatlum, who carded a 9-under 63, birdied 17, second-round leader Korda birdied 15 and Jiyai Shin birdied 18 to finish at 63 all at about the same time to get to 19-under.
Choi gave a fist pump on her birdie putt on the 15th, but the ball wiggled out, and she stayed at 19-under.
Phatlum finished with three straight birdies to walk off the course at 20-under.
Johnson pulled even with a birdie on the par-5 16th after leaving her eagle putt about a foot short.
Despite having to take a free drop when she overshot the 16th and the ball rolled against the TV-camera tower, Korda stayed in contention by getting a birdie on the par-5 to join Johnson and Phatlum at 20-under.
Johnson rolled in a 15-footer for a birdie on 17 to get clear of the clubhouse leader, Phatlum, by going to 21-under.
"Before I hit my birdie putt on 17," Johnson said, "I saw that Pornanong was tied with me at 20, and I didn't want a playoff. So I was like, 'I'm going to make this thing.'"
When Korda put her tee shot on the 17th into the greenside bunker, threw her pitch well over the hole and had her par putt wiggle past the right edge for a bogey, Johnson was two strokes clear of anyone on the course and safely on the 18th green.
She two-putted to finish at 21-under, leaving Choi and Anna Nordqvist in need of birdies on the final two holes to force a playoff. Despite all the birdies dropped during the tournament, neither could do it.
"It means a lot," said Johnson, who won $180,000. "Since I played my first tournament, I was 9, and when I was about 12 or 13, I wanted to play on the LPGA. So like nine years, this is kind of what I've worked for."
Korda came back with a birdie on 18 to finish tied with Phatlum for second.
Shin, 17-year-old Ariya Jutanugarn, Hall of Famer Karrie Webb, Nordqvist and Choi finished tied for fourth at 19-under.
Jutanungarn was playing on a sponsor exemption. In five LPGA outings this season, her worst finish is still fourth.
Defending champion Stacy Lewis, who shot herself back into contention with a 9-under 63 on Saturday, had a 5-under round Sunday and finished alone in ninth at 18-under. Last year, she won the tournament with a then-record 17-under 271, the score that tied for 10th this year, shot by Hee Kyung Seo and first-round leader Lexi Thompson.