World No. 1 Lorena Ochoa tied for fifth-place, ending her string of four straight tour victories.
Creamer's win, on the second playoff hole, was her sixth on the LPGA Tour.
Creamer shot a final-found 72 and Inkster had a 70, capped by a birdie on the final hole, to finish regulation play in 2-under-par 272.
"We have to have a little chat my putter and I, that's for sure," Creamer said after some unsteady putting in the final round.
"Jules (Inkster), what can I say? She definitely made me win it. It was some interesting golf out there. It was a good two-hole playoff.