Sörenstam dominated American Hurst from the start of the 18-hole playoff. She compiled a five-stroke lead after nine holes before patiently playing through the back nine to win by four shots at the Newport Country Club course.
Sörenstam flirted with US Open wins in 2002, 2003 and 2004 but it has been ten years since her last victory.
“Wow, it is fantastic,” said Sörenstam, who shot a one-under 70 on Monday “What a great finish. I kept telling myself ‘play your game, it is good enough. Don’t think about the surroundings.’ I was telling myself so many things that if someone saw me they would think I was crazy.”
Only Mickey Wright and Betsy Rawls have more Open victories, with four each, while just three players have won more women’s majors, headed by Patty Berg with 15.
Sörenstam came out with more spark, ramming home an eight-foot putt for a birdie on the first hole to take a quick two-shot lead over Hurst, who took four shots to get down from inside 100 yards at the easy par-five.
A double-bogey at the par-four sixth and a bogey at the par-four ninth left the American in deep trouble.
An overmatched Hurst shot a three-over 74 and failed to end the drought by Americans at LPGA majors – the last eight major winners have been non-Americans.
The playoff was needed after the players played a 36-hole marathon on Sunday, leaving Sörenstam and Hurst tied at the top of the leaderboard at the 3.1 million dollar event.
Playing in her first tournament since taking out US citizenship, Sörenstam would have finished off Hurst 4 and 3 if it had been a match-play format.
“They say the big championships you’ve really got to earn and I worked really, really hard this week to earn this,” Sörenstam said.
“I felt this week was my week early. Ten years is a long time but I’ve learned a lot, like patience, and maybe that’s what I needed to win again.”
Sörenstam has a realistic chance of notching up the most victories in women’s major history, but she is just as concerned about keeping pace with Tiger Woods, who also has 10 majors in the men’s game.
“He’s been calling me every day and cheering me on, which has been really sweet,” she said. “I think he’s been on vacation, and for him to tune into women’s golf says a lot.”
Until this week, Sörenstam had relinquished her LPGA dominance this year after winning the money title for the past five years, but quality never goes out of style and she showed, at 35, that she is far from washed up.
She arrived here sixth on the money list and not exactly brimming with confidence, but enjoyed some fruitful pre-championship work with longtime coach Henri Reis and Thursday’s fog delay proved an added bonus, giving her an extra day to iron out the kinks.
“I actually think that the fog helped me,” she said. “It gave me another day to work on a few things. I’m thankful for that.