Davis Cup quarter-finals on Sunday by beating South Korea's Kwon Soon-woo in straight sets. US Open champion Alcaraz won 6-4, 7-6 (7/1) against his 74th-ranked opponent at home in Valencia, after Roberto Bautista Agut had earlier beaten Hong Seong Chan 6-1, 6-3.
After their surprise 2-1 loss to Canada on Friday, in which Alcaraz lost to Canadian Felix Auger-Aliassime, the Spaniards won in the singles against South Korea.
First in Group B ahead of Canada, the Spaniards will participate in the quarter-finals in November, in front of their home crowd in Malaga.
Serbia have been eliminated. In Hamburg, Germany took the top spot in Group C ahead of Australia after doubles pairing Kevin Krawietz and Tim Puetz's 6-4, 6-4 victory over Matthew Ebden and Max Purcell.