Millman pulled off the historic upset over Federer in their fourth round matchup, 3-6 7-5 7-6 (9-7) 7-6 (7-3) to reach the quarter finals of the singles tournament, the first time in his entire career Millman has reached the final stages of a Grand Slam event.
7-6 (7/3) victory in his first Grand Slam fourth round match scuppered a blockbuster quarter-final between Federer and two-time victor Novak Djokovic.
Not since Pat Rafter handed a tantrum-throwing Federer a tennis lesson on the then-18-year-old's grand slam debut at Roland Garros in 1999 had an Australian conquered the great Swiss at a major. He's been a hero of mine, and today he was definitely not at his best, ' Millman said, 'but, you know, I'll take it'.
WHAT IT MEANS: We're one step closer to a much-anticipated Djokovic-Roger Federer quarterfinal, which would be their 47 meeting on the ATP World Tour (Djokovic holds a slight 24-22 advantage) and their seventh at the US Open.
"I felt like a deer in the headlights to begin with, to be honest", he said.
While few gave the Brisbane baseliner a chance, Federer had full respect for Millman, having invited him to Switzerland before Wimbledon this year to prepare for the grass-court season.
"I've got to control the controllable and the one thing I can control is the fight in me".
Earlier on Saturday, Federer's 51 winners included a jaw-dropping flick around the net post as he swept aside Nick Kyrgios 6-4 6-1 7-5 to reach the fourth round in a 17th consecutive appearance in NY.
"I'm not 21 anymore".
The Australian is ranked No 55 in the world and for his heroics will be rewarded by a quarters clash against Novak Djokovic. "Sometimes, you just have to survive".
Both Nishikori and Djokovic missed last year's U.S. Open with arm injuries.
The other quarterfinal on the bottom half of the draw will be 2014 runner-up Kei Nishikori against 2014 champion Marin Cilic or No. 10 David Goffin.
The 29-year-old, who was born in Brisbane and is now ranked 55th in the world, was up two sets to one against the Swiss juggernaut and prevailed in a gripping fourth-set tie-break to win 3-6, 7-5, 7-6. 7-6.
He reached the quarterfinals for an 11th consecutive appearance in NY as he bids for a third US Open championship and 14th Grand Slam trophy.
Kohlschreiber was denied again in his fifth attempt to win a fourth-round match at the US Open.