Jeeno keeps cool to win LPGA's Americas Open
The world number two shot a solid three-under-par 69 to win by four strokes from France's Celine Boutier, who shot an even-par 72 in her final round.
Jeeno finished 17-under for the week after staying out of trouble and making birdies on the first, ninth and 17th.
The 22-year-old Thai star had finished off last season with victory in the Tour Championship in November and won on the Ladies European Tour in Saudi Arabia in February.
The win in Jersey City was her 11th professional victory on all tours, but having started her round with just a one-stroke advantage over Boutier, said she had no clue of the leaderboard situation as she approached the final hole.
"I had no idea. Maybe on the last putt because I didn't even look at the leaderboard at all, to be honest. I just asked my caddie if I need to make a par or not. He said, 'It's OK, I think you're safe'. I was just like, OK, so actually I can breathe now," she said.
Jeeno said that tricky pin positions combined with the weather had made it a battle to make par.
"Bogey-free on the final round, final group, as well, because the pin positions were so tough today, as well. We got a lot of wind, and then a lot of nerves and excitement for sure.
"I just really told myself to be patient out there. I know I was just trying to keep my ball where I have a chance to make it, but if I not make it, I'm fine because I know not every putt or not every hole that we're going to make it for sure. But I think my big key today is making par," added the Thai, who finished a disappointing tied for 24th at last week's first major of the year, the Chevron Championship.
Boutier cancelled out her three birdies with three bogeys but was pleased to be in contention as she looks forward to the next major, the US Women's Open in Wisconsin in June.
"A very solid week overall. Definitely a little bit disappointed with my finish today, but feel pretty happy with where my game is at," she said. "Just need to tweak a few things before my next tournament, which is the US Open, so it's very encouraging to have a good result here at such a good tournament."
Spain's Carlota Ciganda and the USA's Andrea Lee finished tied for third place.
Defending champion and world number one Nelly Korda had started the day in contention, just two shots behind Jeeno.
But while the Thai progressed, Korda had four bogeys in a one-over 73.