Daly-Donofrio was steady down the stretch and finished at 15-under-par 273, one stroke better than Mhiari McKay (70) and third-round leader Moira Dunn (72).
The win comes as her first in four seasons on the LPGA Tour.
I really didnt think this was going to happen, said Daly-Donofrio following her performance. Just before I was ready to play Thursday, I was afraid to pick up a club.
Her fear came not from a lack of confidence, rather a terribly sore back.
In fact, the former head golf coach at Yale University was on the brink of withdrawing prior to the start of play.
Now, all is better though, and she is $120,000 richer.
This whole weekend turned out to be a blessing, she exclaimed. I didnt think this (win) would come for me for a couple more years.
While Daly-Donofrios victory was a landmark, good play has not necessarily been so.
Six times now, she has finished inside the top-15 in 2001. In May, she took the lead into the final round of the Chick-fil-A Charity Championship, but closed with a disappointing 75.
It was nothing like what she did this week.
So whats her newfound secret?
'This time around I was so much more confident,' said the champion. 'I have been hitting the ball more solidly. Hitting the greens and fairways often is a big key for me.'
Full-field scores from the Betsy King Classic