Rafael Nadal came back twice from a break down against Japan’s Yoshihito Nishioka to put Spain into the ATP Cup quarter-finals in Australia.

The world number one won 7-6 (7-4) 6-4) to give Spain an unassailable 2-0 lead in the tie after Robert Bautista Agut had earlier beaten Go Soeda 6-2 6-4.

Nadal then paired up with Pablo Carreno Busta to win the doubles rubber and end Japan’s chances of a last-eight spot.

Argentina later beat Croatia to advance to the knockout stage.

Canada and Belgium sealed the two remaining quarter-final spots as the best runners-up.

The knockout stage, taking place in Sydney, begins on Thursday with Great Britain facing hosts Australia (from 23:00 GMT on Wednesday).

The ATP Cup is a new 24-nation knockout tournament that has been set up by the men’s professional tour to kick off the 2020 season.

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Nadal aims to ‘increase level’ after errors

Spain, who won the Davis Cup – another men’s team tennis event – in November, ended their group-stage campaign with a perfect record of nine wins.

But an unusually sluggish Nadal was made to work hard against world number 72 Nishioka, making 19 unforced errors and dropping serve twice in the first set.

It was the first time Nadal, who has not dropped a set at the tournament yet, had played in the hot conditions of the Perth day session.

“It’s the first time I played under these heavy conditions, so the feeling on court is completely different,” Nadal, 33, said.

“I think it’s been a positive week for me winning against three tough opponents,” he added. “It’s going to be tough in Sydney. I really hope to be ready to increase my level.”

Nadal can equal Roger Federer’s record of 20 Grand Slam singles titles at the Australian Open, which starts on 20 January, but the Spaniard said he was not thinking about catching the Swiss great.

“My only goal is to keep playing good tennis, keep enjoying this sport and being happy,” he said. “And if that happens and I stay healthy then the goal is to keep producing chances in the events that I’m going to play.”

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Quarter-final line-up completed

In a winner-takes-all tie between Argentina and Croatia in Sydney, Guido Pella beat 2014 US Open champion Marin Cilic 7-6 (7-1) 6-3 before Diego Schwartzman swept aside Borna Coric 6-2 6-2 to put the South Americans through to the quarter-finals.

Belgium – who were runners-up to Great Britain in Group C – clinched a place as one of the best second-placed teams, while Canada took the final spot for the knockouts.

Novak Djokovic’s Serbia, who had already qualified for the Sydney knockout stage, finished their round-robin campaign with a 2-1 win over Chile in Brisbane.

“Sydney’s got a big Serbian community, hopefully the support can be as good as it was here, even better,” said 16-time Grand Slam champion Djokovic, who beat Cristian Garin 6-3 6-3 to make it three singles victories and one doubles win so far.

France and Croatia had chances to go through but failed to take them.

France needed to beat South Africa 3-0 but lost 2-1 despite captain Gilles Simon stepping in as a late replacement for the injured Gael Monfils to beat Lloyd Harris in the opening match.

Benoit Paire failed to serve out the match twice against Kevin Anderson and had a match point saved in a 2-6 7-6 (7-1) 7-6 (7-5) loss.

Croatia meanwhile, would have gone through if they had beaten already-qualified Argentina in the doubles, but Ivan Dodig and Nikola Mektic lost to Maximo Gonzalez and Andres Molteni on a deciding tie-break.

In the tie between already eliminated Georgia and Uruguay in Group B, a fuming Pablo Cuevas packed his bag and walked off court after getting a warning from the umpire – before his opponent Nikoloz Basilashvili went after him and persuaded him to resume the match.