Rafael Nadal gave Spain a winning start to their Davis Cup semi-final but he was made to work hard by Sam Querrey.

When Davis Cup debutant Querrey, a late replacement for James Blake, was pitted against world number one Nadal in the opening rubber, it looked like being an epic mis-match in front of a partisan home crowd in Madrid's Las Ventas bullring.

But that proved far from the case as the 20-year-old Querrey gave Nadal a scare by taking the first set before the Spaniard finally got going to seal a 6-7 (7/5) 6-4 6-3 6-4 win.

Playing on his favoured red clay - a surface he had only lost once on in well over three years - Nadal may have been slow out of the blocks but he still looked to have gained the upper hand in the 11th game of the first set when Querrey fell 0-30 behind on his own serve following two unforced errors.

Nadal was unable to capitalise on that though and Querrey hit back to send the set to a tie-break, where the giant American - who had taken his opponent to four sets in the fourth round of the recent US Open - quickly gained the upper hand before stunning the home crowd by winning through 7-5.

That was not the start the Spanish had expected, or hoped for, but it was to get worse for Nadal as he then suffered the first break of the match in the opening game of the second set, before Querrey held to take a 2-0 lead.

The possibility of a shock upset looked on the cards at that point, but Nadal showed his class by winning the next three games before breaking Querrey for a second time in the 10th game to take the second set 6-4.

The third set proved more comfortable for Nadal, who broke world number 39 Querrey early on to help establish a 4-1 lead before winning 6-3.

The fourth set was an evenly-fought affair early on, although Querrey had to save two break points in the seventh game before the big-serving American bounced back to push Nadal close in the eighth game.

It was the ninth game that proved decisive through, with Nadal making the breakthrough before the Spanish ace subsequently served out to love to clinch the rubber and give the host nation a winning start.