Wowzers. No wonder Andy Murray is puffing out his cheeks in surprise.

Gigi Salmon
BBC Radio 5 Live

That was the seventh winner for Auger-Aliassime while Murray has yet to record one.

Confident stuff from the 20-year-old, who is playing in the imposing Ashe (even without fans) for the first time.

A 130mph ace down the middle is followed by a 125mph one out wide for a 30-0 lead.

Murray pegs him back to 30-30 before he plugs into the mains again, a ferocious forehand winner and a second serve ace clinches the hold.

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live

Regarding Auger-Aliassime, when you see aggressive baseliners like him, playing at a high tempo... he looks confident.

More power in that right arm then a jackhammer.

FAA overcooks the first break point with an over-eager forehand but takes his second opportunity with some more pummelling.

Warning sign for Murray.

FAA goes toe-to-toe in a baseline battle, trying to test Murray's fitness no doubt.

It works. Murray goes into the net with a forehand and FAA has a break point...

A wayward forehand from the young Canadian puts Murray within a point, but he has to scamper for a shorter ball and can only swipe into the net.

Deuce. Murray's opening service game in a spot of bother.

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live

It's a balance for Andy here. It's the first meeting between the pair, and Andy will want to figure things out.

Murray came to the US Open off the back of three matches having not played much before that. Coming through that long match in the first round will give him confidence that his body can cope.

An early look at the Murray serve for FAA, who swats away a forehand winner for 15-30.

Murray struggled to land first serves in the first part of his match against Yoshihito Nishioka, that must change today one would imagine.

One lands and forces FAA into the net to prove that point. 30-30.

Carlos Ramos in the chair by the way.

Hope there is a one-way system in operation backstage, otherwise there could have been an awkward meeting in the corridor with Serena Williams.

Cracking start for FAA (we're going with his initials at such an hour).

He races 40-0 ahead thanks to a rapid forehand winner down the line after a 107mph second serve, then whacks down an ace to seal the deal.

Lively.

I'm fully prepared to see the bin man outside my window during the fifth set...

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live

I am in the kitchen, but I've got a piece of kit to join up with you guys for this match.

If it's like the last Murray match then we might be here for a while.

Felix Auger-Aliassime has the honour.

Ready? Play.

More from Murray on playing Auger-Aliassime for the first time: "It is always tricky playing someone who you have never played before.

"He's got a big game, I don't want him to dictate and when I get the opportunity I will try to put him on the defensive side."

Andy Murray, speaking in his on-court interview about his recovery: "I didn't do a whole lot of activity, I spent a bit of time in my room, had an ice bath, lot of time with my physio, light practice yesterday and tried my best to recover."

Rackets, water, surgical masks... the players are arriving on Ashe. I still can't my head around watching matches here without seeing Fan-Cam, Kiss-Cam and Celeb-Cam doing its thing.

So I think we can agree that Murray deserved as much rest as possible.

That's why the former number one asked for this late start.

We'll forgive him.

Image source, Reuters

And this is why.

On Tuesday, Murray beat Japan's 49th-ranked Yoshihito Nishioka 4-6 4-6 7-6 (7-5) 7-6 (7-4) 6-4 - in his first singles match at a major since January 2019 after hip surgery.

Extraordinary tennis player. Extraordinary human.

The big question is how will Andy Murray - a 33-year-old with a metal hip who played a four-and-a-half hour match two days ago - be physically.

Felix Auger-Aliassime has got a heck of an engine on him. Murray might not have as much in the tank.