Rafael Nadal answers in kind with a hold of his own. He is walking a tightrope now though. One slip and, from what we have seen so far, he can't rely on Tim Smyczek's nerves to open up a route back into the match.

Image source, AP

Tim Smyczek is deep in the groove though.

The American holds to love, "Never mind winning, I want it done in four," that seemed to say.

He is hitting winners from all over the court. What with Kyrgios, Rosol and Darcis in his past, Rafael Nadal does seem to walk into these one-hit wonder ambushes more often than any of the game's other megastars.

I'm not sure that Novak Djokovic for example gives the likes of Smyzcek a play on the ball in the first place to see if they can get lucky.

Leon Smith
GB Davis Cup captain on BBC Radio 5 live sports extra

"This is a huge opportunity for Smyczek but it's going to take a huge effort to get over the line. Rafael Nadal will fight, fight and fight and make it so difficult for Smyczek and he will be much more aggressive."

Rafael Nadal has been back to the bathroom for a long look in the mirror.

He looks a lot better for it and romps into a 40-0 lead. His forehand seems to have regained some zip - he works over Smyczek off that wing to seal the game.

Rafael Nadal holds for 4-2, but a deep return from Smyzcek has Nadal in trouble in the next and another mighty forehand whack gives the American a double mini-break and 5-2. He holds for 6-2.

Pressure now with set points aplenty.

Boom! Ace spits down the middle and this upset is more than brewing. It is almost ready for drinking.

Tim Smyczek takes the mini-break for a 2-0 lead as he races in to take on the volley and cut down Nadal's time. Rafa's pick-up half volley creeps long. Nadal holds his serve second time around, but is left as a spectator by Smyczek's rifled back hand. The American is 3-1 to the good and will receive serve at 4-1 to the good as a Nadal pass flies wide.

Leon Smith
GB Davis Cup captain on BBC Radio 5 live sports extra

"Nadal is such a fighter. He is clearly feeling unwell but is going deep within himself to fight. That was a good hold."

Tim Smyczek is certainly playing well - one back-to-the-net trick shot return as he chases back for a lob is particularly cheeky.

But this is Rafael Nadal with the handbrake on and a parachute out the back.

The Spaniard has done enough to take the underdog into a tie-break.

As he climbs towards would be the highest peak in his career so far, Tim Smyczek still not looking down. Not a hint of vertigo as he serves out in assured style.

Rafael Nadal is still looking like he wants a sicknote handed down from Uncle Toni and to come back tomorrow.

Seventy minutes on the clock for the third set. The first two weighed in at a combined total of 71 minutes.

Tim Smyczek is firing on all cylinders.

A searing passing shot brings the crowd to the feet and sends the scoreboard ticking on to 0-30.

A lovely tickle of a backhand dropper is beyond the reach of Nadal and sets up two break points.

And Nadal hands over the first with a double fault.

This is still on.

Image source, Reuters

As he collects balls and prepares to serve for the set, Rafael Nadal suddenly looks a little peaky.

A couple of deep swallows from the Spaniard before he heads to the back of the court and ejects some fluid from his mouth.

He is not the full ticket certainly...

A big service game did I say?

Well, Tim Smyczek brings his A-grade arsenal to the party, peppering the Nadal service box with laser-guided missiles.

A sublime backhand winner strafes an advancing Nadal when the rally gets beyond the opening shot.

A hold to love.

Image source, EPA

A sitdown and a mental reboot for Tim Smyczek at the changeover. That seems to have sorted out the gremlins in the American's game. A fizzing inside-out forehand moves him 0-30 up.

He whips away down the same wing for 15-40 and three break points.

What have you got Rafa?

Enough it turns out. The Spaniard adds a little spice to his serve to whittle away the first break point and then comes rushing to the net to shut down the angles and close the door on the second.

A crunching ace closes the game. Nadal snarls up to Uncle Toni in the players' box and he gets a nod in response.

A big service game coming up for Mr Smyczek.

Vamos!

Rafael Nadal uppercuts thin air as he hammers away a backhand volley to move to break point from advantage.

Tim Smyczek still has a bit of punch left though. He climbs into a high forehand to swat away an irrecoverable winner.

A similar stroke saves a second break point, but errors are starting to crop up like weeds in Smyczek's game.

He is taking a little longer to sort out his footwork, his groundstrokes are lacking a little length and the third break point is the charm for Nadal.

Image source, Getty Images

One hundred and nine ranking places between them, but not much more than a cigarette paper difference on court where it matters.

This doing a very good impression of the first set of a match between two of the top guys rather then the third set of Nadal v a qualifier.

Both players serves coming under pressure, but surviving. Nadal holds to 30 and it feels like we have the tipping point of the match.

Alison Mitchell
BBC Radio 5 live sports extra commentator

"I just wonder if Nadal calling for the doctor and the delay in play has halted some of Smyczek's momentum?"

Image source, Reuters

Is this the tide turning?

Tim Smyczek has been the man making things happen for the last set of so, but finds himself break point down.

Re-check the shipping forecast.

The American has held up well under pressure and after mistakes so far and cleans the mental slate to win the next two points.

Image source, Reuters

Nothing settles the stomach better than a solid hold of serve.

Rafael Nadal certainly looks no worse after the medical timeout as he retains his serve with Tim Smyzcek leaving just one point's worth of damage.

Marc McPherson:, external Take Nadal out of the mix early on, and we're in for a very interesting grand slam...

Leon Smith
GB Davis Cup captain on BBC Radio 5 live sports extra

"It doesn't look like Nadal has a physical injury. It's the doctor on court rather than the physio. It must be some kind of illness.

"There's something not quite right about him and it'll be interesting to see how Smyczek responds and whether he can use to that to his advantage and make Nadal work hard for his points and and make him run as much as he can."