'I'm so happy. It feels good,' said Han, who pocketed $142,500 for the win. 'If I miss that four-footer on 18, I could still two-putt and win, it was a nice feeling.'
Grace Park fired a 3-under 68 to finish in a tie for third at 5-under- par 279 . She was joined there by Cindy Figg-Currier, who shot a 1-over 73.
Han began her round at Wykagyl Country Club in a tie for first with Mallon. Mallon bogeyed the second and fifth to fall off the pace.
Han meanwhile began her round with four straight pars before a six-foot birdie at the fifth gave her a three-shot cushion over her playing partner.
The South Korean dropped back to minus-9 after a double-bogey at the par-4 eighth, where she missed the fairway left and took two shots to get back to the fairway. Mallon bogeyed the ninth after missing the green to drop to 8-under for the tournament.
'That's the point where I really needed to take off when she was making double on eight, and I had it sitting right there in the fairway with a wedge in my hand,' said Mallon. 'I hit a wedge and it ended up checking and staying on the front. That's where I really felt like I had a better opportunity to try and cut the lead a little more there. Then I turned around on No. 9 and hit a bad drive.'
Han, the 2001 rookie of the year, birdied the 10th from three feet out to extend her lead to two shots. Mallon fell further back when she drove into the trees on No. 12, which resulted in a bogey that dropped her to minus-7.
Han came back to the field with back-to-back bogeys from the 13th. She ended that slide with an up-and-down birdie at the par-5 15th to move back to 10-under. Mallon also birdied No. 15 from three feet to get back to minus-8.
Han dropped her third shot within four feet at the 18th to set up birdie, which gave the title by two shots.
'If I get more attention after this event, I am going to try to show them a better performance,' Han said through her translator. 'I'll be happy to do that.'
Mallon nearly eagled the 18th from over 60 feet but her putt ended within inches of the cup. She tapped in for a birdie to close her round of 2-over 73.
'As easy as and as good as Saturday was, it was equally that difficult today,' Mallon said. 'I was a little off. Unfortunately, when you're on you get rewarded and if you're slightly off, you have to work hard for pars and making bogeys.'
Michele Redman carded a 2-under 69 Sunday to finish alone in fifth place at 4-under-par 280. Kristal Parker-Manzo, Rachel Teske and Denise Killeen tied for sixth one stroke further back at minus-3.
Gloria Park, the 2002 champion, shot a 5-over 76 in the final round to end the event at 3-over-par 287.
Suzy Whaley, who will tee it up at the PGA Tour's Greater Hartford Open next weekend, carded a 1-over 72 in the final round and finished at 7-over- par 291.