Not phew.

Querrey double faults and Nadal gets another break point.

Phew.

Nadal's backhand goes into the net. Break point saved.

Only once before, in 2007, have Novak Djokovic, Roger Federer and Rafael Nadal made it to the Wimbledon semi-finals at the same time.

And the Spaniard looks keen to make it happen again as he attacks Querrey's second serve to bring up break point.

Nadal might soon give Federer what he wants.

The Spaniard slams a forehand winner past Querrey to go 40-0 up, then Querrey's backhand return lands wide.

One game closer.

Image source, Getty Images

More from Roger Federer, on a potential semi-final match against Rafael Nadal: "We have a lot of information on Rafa, as does he on us. So you can dive in to the tactics like mad for two days or you say it's grass court tennis so I'm going to come out and play my tennis.

"People always hype it up. It was a joy to play against Rafa on his court at the French Open and it would be if I have to play him here at Wimbledon. I'd be very excited to play him here."

A winning serve out wide and an ace bring up an important hold for Querrey.

Image source, EPA

Roger Federer speaking on BBC Two: "It was very difficult. It was a brutal beginning, Kei came out smashing winners, I just tried to stay with him and tried to turn it around in the first set. But Kei was the better player. I was able to start a normal match at one set all and then I protected my serve really well until the end. I played a good service game against a good return player."

On reaching 100 singles wins at Wimbledon: "It's not like I think I have to get my 100 - I just try to win the next point and then hopefully at the end of the match you have your hands in the air. It was only after the match a fan said congratulations on your 100 and I was like 'oh yeah, it's my 100'. It's so nice, and getting it against Kei is very nice."

Smart work at the net from Querrey as he taps a volley over the net. Break point saved.

Querrey jumps in the air like a frustrated toddler as Nadal's backhand return lands on the line. Break point.

Nadal puts his head in his hands as he cuts a backhand wide. 30-15.

Querrey probably doesn't have much chance, but if he's to have any he really needs a hold here.

The American hits the ball long and it's 30-30.

Nadal is quickly at 40-0, but falters as he hits a backhand into the net.

He can't be held off for long, though, and smacks a speedy forehand down the line. Another hold.

"We have a lot of information on Rafa..." says Roger Federer of his potential semi-final opponent with a smirk, while wiping the one bead of sweat on his brow away with his hand.

More from Fed in a moment...

Uh oh. You know it's bad when there's a double fist pump.

Querrey puts up what should have been a winning drop shot but Nadal sprints forwards and angles a perfect forehand winner.

Querrey gets Nadal moving and the Spaniard hits a forehand into the net. One break point saved.

An ace sorts out the second one.

Sonia Oxley
BBC Sport at Wimbledon

On Court One you could hear the cheers coming over from Centre after Federer won.

Seconds later Nadal took the second set here.

The semi-final all the neutrals want is tantalisingly close.

Image source, Getty Images

Is this the beginning of the end for Querrey?

He loops a forehand way wide to go 0-30 down on his serve.

Nadal challenges and the ball has landed long, three break points.

And that was Roger Federer's 100th match win in the singles at Wimbledon.

Raise that racquet to the crowd...

Roger Federer whips off his sweat bands and tosses them into the crowd - a slightly smelly souvenir for a spectator or three.

The Swiss great stops on his way off Centre Court to sign some novelty tennis balls, programmes, pieces of scrap paper. You name it...

Nadal actually managed to serve more aces than Querrey in that set - unheard of. He served four to the American's three.

Andrew Cotter
BBC Sport commentator at Wimbledon

Roger Federer has felt this feeling so many times before.

But, still, it means so much to him.