Pablo Carreno Busta guaranteed Spain’s spot in the ATP Cup semi-finals on Friday with a 6-3, 6-4 win against Greece’s Michail Pervolarakis.

World No. 2 Rafael Nadal, who led Spain to last year’s championship match against Serbia, has not yet competed in this edition due to a stiff lower back. But Spain has battled on with two of the Top 20 players in the FedEx ATP Rankings: World No. 16 Carreno Busta and World No. 13 Roberto Bautista Agut.

"I knew that we needed this point. With this victory, we are into the semi-finals, so it was very important to us," Carreno Busta said in his on-court interview. "I tried to be focussed on myself, to try to play my [best] game]."

Carreno Busta has stepped up well for his country, winning both of his singles matches — he also defeated Australian John Millman on Tuesday — in straight sets. The Spaniard broke in his first return game of the match, and he never looked back.

The 29-year-old Carreno Busta made few mistakes from the baseline, forcing Pervolarakis to play outside of his comfort zone and go for too much. The World No. 462 battled hard to hang in there despite losing the first five games of the match, even eliciting a round of applause from Nadal after he won his first game. But the Greek was unable to consistently go blow for blow with the four-time ATP Tour titlist in longer rallies.

Carreno Busta maintained his steady level throughout to triumph after 70 minutes. The former World No. 10 has only lost 13 games in four sets.

"At the beginning of the match, I think it was perfect. I played really good," Carreno Busta said. "Then he started to play better, to play more aggressive and I tried to continue. Finally 6-3, 6-4 I won and I'm happy."

Pervolarakis was pursuing the first ATP Tour win of his career. The Greek had to defeat Carreno Busta to give his country a chance at advancing to the semi-finals.

Stefanos Tsitsipas, the 2019 Nitto ATP Finals champion, kept Greece's hopes alive in the tie by defeating Bautista Agut 7-5, 7-5.

The World No. 5 played impressive attacking tennis to defeat the always-solid Spaniard after one hour and 41 minutes.

"It was a good match. I think I played very solid throughout the whole match and showed aggression. My forehand was on fire, my serve was working really well for me," Tsitsipas said in his on-court interview. "I executed my game plan very well and had a clear picture of what I was intending to do out on the court."

Tsitsipas had the action on his racquet for the majority of the battle. The Greek star had three match points to close it out at 5-2 in the second set, but Bautista Agut held his serve, and then broke Tsitsipas in the next game with a backhand return winner.

Eventually, Tsitsipas' pressure proved too much for the game Spaniard. Bautista Agut hit his first double fault on the final point of the match.

Tsitsipas now leads the pair's ATP Head2Head series 2-0, and both of those matches have come at Melbourne Park. The Greek triumphed in four sets in the 2019 Australian Open quarter-finals to become the youngest Grand Slam semi-finalist since a 20-year-old Novak Djokovic at the 2007 US Open.

Tsitsipas and Markos Kalovelonis returned to John Cain Arena to take on Carreno Busta and Marcel Granollers to decide the tie. But after Greece won the first game, Spain retired. That gave Greece its first tie victory in event history.