Federer, flustered? Not yet. This man could be being eaten alive by a boa constrictor and not break sweat until he was naval deep. Hold at pace, pressure straight back on the Kid From Nowhere. 

Settled? He's right at home. A hold to love, a lead in the third, the crowd screaming his every shot. Remember, Willis is the British 23. There is no 15-22.

Richard Krajicek
On Radio 5 live at Wimbledon

I think the bookies have learned from Leicester. I have to say 250-1 is not really great odds - even in a two-horse race.

Colin Steer: Go for it Marcus, you are giving us the GREAT back in Great Britain.

Tom Ng: Am living vicariously through Marcus Willis at the moment.

Federer shanks a regulation forehand volley onto the tape and wide, and for a moment it's 15-30 and it all seems possible. Hold on to your beverages - break point, a pop at micro-glorty, Federer in... ach, marmalises the overhead, and the sparks are snuffed out.

Image source, Getty Images

Johanna Konta is through to the second round after beating Monica Puig 6-1 7-5.

John McEnroe
Three-time Wimbledon singles champions on BBC TV

When was the last time a club player came back from two sets down...?

Pat Cash
Former Wimbledon champion on BBC Radio 5 live

Federer has his game face on. He knows Willis' left hand serve is fantastic practice for him.

He may not meet another left-hander, but it helps to get your eye in.

There is more coverage on BBC Radio 5 live sports extra right here or by clicking the tab at the top of this page.

Image source, Getty Images

The wheels came off for British number two Heather Watson in that second set. A chunky bagel served up by Annika Beck and we are in for a decider for dessert.

And the Guernsey woman has coughed up her serve at the start of the third as well.

"Willis leads, three games to two..." intones our umpire, before adding apologetically, "Federer leads two sets to love." Willis waves to the crowd, revving up an engine that's already roaring in fifth gear.

An hour into a fast-forward contest, and Willis going toe to toe with one of the greats. Only very rarely does Centre Court permit anyone else support when King Roger is in his kingdom, but Marcus has the unequivocal backing.

Image source, Getty Images

Carumba - super backhand from the back of the court, Federer pinned at the net like an exotic butterfly to a card. The lad can play, no two ways...

Not sure how Willis gets a toehold in the Federer serve. He can't get a fingernail in that game, but let's see.

Richard Krajicek
On Radio 5 live at Wimbledon

If Willis wins today, will Federer take his place in Coventry tomorrow?

Roy: Drag the English Football team in to watch this. They could learn much.

Tellytruth: Marcus Willis is the new Eddie the Eagle.

Abdullah Mahmood: Marcus Willis is my new spirit animal.

Andrew Castle
BBC Sport tennis commentator

I think Marcus' girlfriend should take a shot of the scoreboard there. 

Sharing a court and scoreboard with Roger Federer. It is an experience he is enjoying and at 6pm he is playing better in the match now.

If you're watching/about to watch on television, we're about to switch from BBC One to Two. My pleasure. Willis to 40-0, Federer hauling him back to deuce, sweet ripping pass down the line to level it up. Crowd going ripe bananas.

Image source, Getty Images

Watch Willis treated rather harshly for his choice of mid-match snacks in 2014.

Image source, Getty Images

British number one Johanna Konta is through after wrestling home a see-sawing second set against Puerto Rico's Monica Puig.

Who's next?

Well, it could be Canada's 2014 runner-up Eugenie Bouchard who has been going through a rocky patch but is a set up on Magdalena Rybarikova.