SYDNEY -- Pablo Carreno Busta beat Filip Krajinovic 6-3, 6-4 to secure an ATP Cup semifinal spot for Spain and Roberto Bautista Agut completed the group-stage victory over Serbia with a 6-1, 6-4 defeat of Dusan Lajovic later Wednesday in the second of the singles matches.
Spain only needed to win one of the three matches against Serbia to top Group A and set up a semifinal against Poland.
Carreno Busta got the job done in 80 minutes, registering his third singles win of the round-robin stage.
"It was the best match of the group," Carreno Busta said in a post-match interview. "I am close to 100%. Today I played very well, very aggressively, very solid. I feel very comfortable on court, so it is going well."
Spain dropped only one set on its way to victories over Chile, Norway and Serbia, the 2020 champions.
Chile's 2-1 win over Norway in the day session meant Serbia needed to sweep Spain to advance.
Alejandro Tabilo beat Viktor Durasovic 6-1, 6-7 (5), 6-1 to give Chile the lead before No. 8-ranked Casper Ruud leveled it for Norway with a 6-4, 6-1 win over Christian Garin.
Tabilo and Tomas Barrios Vera clinched the doubles 6-0, 6-4, giving Chile a 2-1 record in the round-robin stage and leaving Norway 0-3.
Poland reached the semifinals for the first time when No. 9-ranked Hubert Hurkacz beat Argentina's Diego Schwartzman 6-1, 6-4 following Kamil Majchrzak's 6-3, 7-6 (3) win over Federico Delbonis.
Poland finished the round-robin stage 3-0 in Group D, also beating Georgia and Greece.
"I'm so happy for our team. We're in the semis, so super proud of that achievement," Hurkacz said. "We have great team spirit. We support each other. I think the atmosphere that we bring helps us play better."
Greece picked up its first victory with a 2-0 win over last-place Georgia.
