Uh oh, but maybe that's what Schwartzman needs...

He sends another forehand skipping way off target. Better from the Argentine as a backhand winner drifts beyond Nadal.

30-15.

Jonathan Jurejko
BBC Sport at Roland Garros

The rain has returned...

Diego Schwartzman was look calm and composed before the rain break. Now he's looking frustrated and edgy.

Rafael Nadal to serve for the second set to level things up.

Image source, Reuters

Schwartzman goes long. He wanders over to take a look... but that doesn't change the decision.

Nadal goes a break up.

Rafa Nadal finds pace and depth with a forehand that continues to jump up at Diego Schwartzman.

Three break points for the Spaniard.

Schwartzman cracks the net with a leaping forehand and mutters to himself in frustration.

He pops another long. 0-30 and Nadal on the charge.

Rafael Nadal holds serve. Successive games for the world number one since the return.

Image source, AFP

We are into a tie-break in the other men's quarter-final between Marin Cilic and Juan Martin del Potro.

The Argentine is the one who has had the chances, but has failed to take any of his six break points.

Huge serve, long return from the Argentine. But Rafa pumps off target with his next forehand.

40-15.

Rafa Nadal is steaming into every stroke now, pounding the wet clay and hammering racquet-rattling drives in Diego Schwartzman's direction.

30-0.

Image source, Reuters

Just long from Schwartzman off the forehand side. Nadal breaks back immediately after the rain delay.

The turning point in this quarter-final match? The Spaniard roars in delight.

From power to precision for Schwartzman, getting the better of Nadal with a deft drop shot.

He can't build on it, patting into the net from deep.

Back to deuce, and then he misses a sliced volley at the net.

Advantage Nadal, and a second break point.

Schwartzman leaps into successive forehands and then zips across the clay to wrong-foot Nadal with a marvelous forehand winner.

Break point saved.

First fist pump since we've come back for Diego Schwartzman - the Argentine almost goes around the net to pick out the whites of the Chatrier tramlines.

But he then rattles the tape. Break point Nadal.

It's Rafa who gets the better of the next rally, too. Both arms strapped, the Spaniard edges into a 0-30 lead before cracking a wayward backhand off target.

Image source, Getty Images

Nadal takes the first point since the break, and promptly flattens some clay along the baseline with the sole of his shoe.

Right, this is it, here we go.

Diego Schwartzman leading 6-4 3-2 and a break up in the second set. A massive couple of hours ahead for the 25-year-old from Argentina.

Jonathan Jurejko
BBC Sport at Roland Garros

The two players are back out, a five-minute warm-up begins.

Although I'm sure it has got darker and there's another black cloud to my right...

A bit of celeb spotting, too - Didier Drogba is in the stands at Court Philippe Chatrier. I imagine the former Chelsea striker delivers a mean serve.

A telling stat while we wait...Schwartzman has fired 26 winners today to Nadal's eight.

Image source, EPA