Thirty-one-year-old Serena Williams also became the oldest US Open champion in the Open Era, beating Margaret Court's record of 1973 by 293 days. She also became the third-oldest Grand Slam women's champion of the Open Era.
Serena won the rematch of last year's final to bag her 17th career Grand Slam
She is also the first top-seeded champion since Belgium's Justin Henin-Hardenne in 2007 and the first woman player to have defended the US Open crown after Kim Clijsters, also of Belgium, in 2010.
Williams bettered her head-on statistics with two-time Australian Open champion Azarenka to 13-3 although the latter had won two of their previous three meetings, including last month's Cincinnati Open final.
While Williams lauded Azarenka for her gritty show in the final, the latter admitted that Williams was the superior player of the day and made better use of the windy conditions.