Hurst's late double bogey cost her the win and dropped her into a tie for second. She shot a 2-under 70 to finish at 12-under-par 276 alongside Jung Yeon Lee (70), Se Ri Pak (70), Grace Park (69) and Rachel Teske (70).
The leaderboard was crowded all day at Lincoln Hills Club. Teske, Lee and Hurst all had the lead at one time or another.
Alfredsson was able to survive thanks to her bogey-free back nine. On the front side, she birdied the par-5 second from 12 feet out, but dropped shots at the fifth and ninth.
She was at 10 under heading to the back nine, trailing several players. The Swede began to make her move with a two-putt birdie at the par-5 11th. She came right back to convert consecutive short birdie putts from the 13th to move to minus-13. She had a chance for birdie at the last, but could not convert.
'I had a decent chance of making that putt, but I didn't hit it hard enough and it broke on me,' said Alfredsson.
At that point she held the lead, but Hurst would climb past her.
Hurst began the day at 10 under, one shot behind Alfredsson, her playing partner. Hurst birdied the second and fourth to grab share of the lead with Alfredsson.
Hurst, like Alfredsson, bogeyed the fifth. Hurst came back with a birdie at the eighth to get back to 12 under. She birdied the 10th and later birdied the 15th to get to 14 under, where she held a one-shot lead.
Hurst needed to par in to win. She was able to par Nos. 16 and 17, but the 18th was her downfall. She knocked a wedge onto the front of the green with her second, but four-putted to a double bogey.
'The first three putts were all downhill, so I thought they would be faster than what they were,' Hurst said. 'I had been missing some putts coming in, and it would have been good to have a cushion. I was hitting it close and nothing would fall. That kind of hurt more than 18.'
The double bogey gave Alfredsson her first win since the 1998 Welch's/Circle K Championship.
'When you haven't been playing well, you want it so much,' said Alfredsson, who picked up $150,000 for the win. 'If this is a dream, don't wake me up.'
Alfredsson, despite the win, had mixed emotions about the finish.
'I have mixed emotions, not for me but for somebody else,' said Alfredsson. 'I don't like to see the way Pat finished because she played so well. You wish you could win it outright, but not by someone missing like that.'
Karrie Webb fired a 4-under 68 to move into a tie for seventh. She was joined at 10-under-par 278 by Catriona Matthew (70) and Lorena Ochoa (69). Gloria Park finished one stroke further back at minus-9.
Ochoa made 19 of 20 cuts this season and with that earned the 2003 Louise Suggs Rolex Rookie of the Year award, beating out Young Kim and Suzann Pettersen.
'I'm very excited. This was one of my goals at the beginning of the year and it's nice to achieve your goals and be recognized for your efforts,' said Ochoa, the first rookie of the year from Mexico. 'It's been a hard year for me in many ways, but I'm super happy with the results.'
Cristie Kerr, the 2002 champion, stumbled to a 3-over 75. She finished at 1-under-par 287 in a tie for 35th.