Novak Djokovic in action for Serbia. Image Credit: AP

Sydney: Novak Djokovic had an almost full house on his side at Ken Rosewell Arena, and felt like he needed to be a responsible host for his guests.

There was a delay late in the third set of his ATP Cup quarter-final match against Denis Shapovalov on Friday when a spectator needed medical attention from paramedics and Djokovic, despite being down 0-30 while serving for the match, took a bottle of water over toward the stadium seating and asked the crowd to pass it along.

A tight match went to deciding tiebreaker following two-and-a-half hours, and Djokovic seized control by winning the first five points and then finished off a comeback 4-6, 6-1, 7-6 triumph.

Dusan Lajovic had earlier beaten Felix Auger-Aliassime 6-4, 6-2 and so Djokovic’s win sealed the quarter-final ahead of the doubles match, giving Serbia a spot in the semi-finals against Russia. Serbia won the doubles to complete a 3-0 sweep.

“That was so close, it could have gone in a different way easily. (Shapovalov) was playing terrific tennis,” Djokovic said. “It felt, not a little bit, fully like I’m playing at home.”

Djokovic, who has won a record seven Australian Open men’s singles titles, was playing in Sydney for the first time in a decade after going 3-0 in singles in the ATP Cup group stage in Brisbane.

“I’m mean, Brisbane we had amazing support — but this has taken it to a different level,” Djokovic said. “All the Serbian people came out today.

Rafael Nadal suffered an upset singles loss against Belgium but made amends in the doubles to keep Spain alive.

After Roberto Bautista Agut swept past Kimmer Coppejans 6-1, 6-4 in the first singles match, Nadal had the chance to wrap up a last four berth against David Goffin.

But the 19-time Grand Slam winner struggled in the heat and humidity of Sydney, crashing 6-4, 7-6 to the 11th-ranked Belgium.

It was a rare defeat while playing for his country, who he helped to victory in the Davis Cup in November.

It sent the tie to a decisive doubles match, with Nadal returning to partner Pablo Carreno Busta against Sander Gille and Joran Vliegen in a gritty 6-7, 7-5, 10-7 win.

“It was tough, because for us it was a big change from Perth to here, not much time to adapt and the conditions were heavy, the humidity and playing against big players,” said Nadal.

“But as a team we are super happy to be in the semi-finals.”

Nadal, who had not dropped a set this year before meeting Goffin, struggled to find his rhythm, giving away nine break points in the first set. Goffin had two more break points to go 5-3 up in the second, but Nadal clung on and became more offensive to take the match to a tiebreak before the Belgian closed it out for one of the biggest wins in his career.

Spain will face Australia in the last four.