Neither world No. 1 Williams nor No. 2 Azarenka was really tested in their semi-final matches on Friday at Flushing Meadows with Williams thumping China's Li Na 6-0, 6-3 and then Azarenka dominated unseeded Italian Flavia Pennetta 6-4, 6-2.
Pennetta had made a stunning run to make it through to the semi finals in New York having beaten the likes of Simona Halep, Svetlana Kuznetsova and Roberta Vinci, but the challenge of Belarusian Azarenka proved one hurdle too high for her.
It was a tighter match than the straight-set scoreline suggested with the first set lasting 52 minutes with Pennetta able to break Azarenka's serve on all three break points she created with the Belarusian hitting 18 unforced errors and five double faults.
However, Pennetta was able to win just 53 per cent of her own points on her first serves, and 26 per cent on her second serves to allow Azarenka to break her service four times and take the set 6-4.
Pennetta's service numbers than plummeted further in the second with her winning 40 per cent of only 43 per cent of her first serves that landed, and then only winning two of 13 of her second serves for the set.
That again allowed Azarenka to break the Italian's serve on four occasions to claim it 6-2 and earn her way into the US Open final.
The 24-year-old has won the last two Australian Open titles but has not broken through for another major with her only other final appearance coming at last year's US Open where she lost in the final to Williams so this is her chance to make up for that 12 months later in New York.
Then in the other semi-final, Williams stamped her authority all over the 2011 French Open champion not allowing Li Na to win a game in the first set, and then even though it was tougher in the second the American still cruised into the final with the 6-0, 6-3 victory.
Li was only able to hit one winner for the entire first set opposed to three double faults and 12 unforced errors to allow Williams to dominate, and then even though it was more of a contest in the second set, Williams still hit 15 winners to win it 6-3 in 58 minutes.
Williams is now looking to make it back-to-back US Open titles and five in New York overall and if she is able to beat Azarenka in the final, it will give her 17 majors in her career that is showing no signs of slowing down.
Not only will Azarenka need to turn around the result from last year's US Open final, but to also turn around Williams' dominance against her overall.
The American has won 12 of the 15 clashes between the two but more importantly six of them have been at Grand Slam tournaments and Williams has won all of those.
The first two came at the 2008 and 2009 Australian Opens before Williams also winning at the 2009 Wimbledon, 2010 Australian Open, 2012 Wimbledon and the US Open final of last year that Williams won 6-2, 2-6, 7-5.
Azarenka is fully aware of what she is up against with Williams in the final on Sunday, but is looking forward to the challenge and takes confidence out of having beaten her twice so far in 2013.
"It's an amazing opportunity and something that every tennis player dreams of to be in the final of the US Open and play against the best player in the world," Azarenka said.
"It's something that I'm so excited about and I can't wait to go out and play. Right now, though, I just want to enjoy the moment of today because we play in two days time.
"It's really just about taking each other out of their comfort zones and just fight for every ball because we know each other pretty well. I know her strengths, she knows my strengths and it's about those turning points, and who wants it more.
"You've got to fight against her and you've got to run, you've got to grin and you've got to bite your teeth for whatever opportunity you have. She's obviously an amazing player and the great of all-time."