Brisbane - John Millman stunned Felix Auger-Aliassime in straight sets to help guide Australia to victory over Canada in their ATP Group F tie in Brisbane on Sunday.
Millman was called upon to play singles only hours before the opening rubber of the tie when the mercurial Nick Kyrgios withdrew with back soreness, but he had no trouble accounting for the higher-ranked Auger-Aliassime 6-4, 6-2.
The Australians sealed the tie when a tenacious Alex de Minaur came from a set down to beat Canadian number one Denis Shapovalov 6-7 (6/8), 6-4, 6-2 in three hours.
John Peers and Chris Guccione made it a clean sweep for the home side when they beat Auger-Aliassime and Adil Shamasdin with a match tiebreaker 3-6, 7-6 (7/3), 10/8.
Millman said he wasn't perturbed about getting the late call-up and said he relished playing on his home court in hot and humid conditions that favoured him rather than his Canadian opponent.
"I was pretty prepared -- it's always difficult, a late call-up, but it doesn't get much easier in a difficult circumstance than when you get to play here in Brisbane, a place where you're familiar with the court and the surroundings and you know that you're going to have a vocal crowd in your corner," Millman said.
"Those humid conditions, what they do is the humidity actually creates heavier conditions.
"You feel like you can really cover the ball and really give it a good swing on that ball, and that humidity, that heavy air is going to bring it down.
"They're the conditions I really like to play in and it's no surprise that it's what I grew up in. It's like playing a Spaniard over in Spain, you don't want to do it."
De Minaur again showed the fighting qualities for which he is renowned.
Just as he did against German number one Alexander Zverev in their opening tie on Friday, de Minaur recovered from losing the first set to overwhelm Shapovalov and clinch the tie.
Australian captain Lleyton Hewitt said Kyrgios had woken up in a bit of discomfort after his win over Jan-Lennard Struff in the first tie against Germany and was rested as a precaution.
"I think with Nick he hasn't played a lot of matches," Hewitt said.
"He probably hasn't had the biggest pre-season either, so after his first round he was probably going to pull up a bit sore.
"We'll test him out again tomorrow and see where he's at."