Backed by a passionate home crowd in Busan, South Korea came from behind to defeat Argentina 3–2 on Sunday in the opening round of Davis Cup qualifying.
Elsewhere, record 32-time champions the United States eased past Hungary, Belgium secured victory in Bulgaria, and the Czech Republic wrapped up a win against Sweden.
Argentina’s Guido Andreozzi and Federico Agustin Gomez had earlier put the visitors 2–1 ahead by defeating Nam Ji-sung and Park Ui-sung 6–3, 7–5 in the doubles.
However, South Korea fought back when Kwon Soon-woo overturned a deficit against Thiago Agustin Tirante. Despite being ranked 248 places lower, Kwon recovered to win 6–4, 4–6, 6–3 and level the tie.
Hyeon Chung then sealed the victory, handling the pressure to beat Marco Trungelliti 6–4, 6–3 in the deciding match.
Kwon, who is still completing his military service, credited the crowd for lifting his performance, saying their loud support helped him stay focused.
None of the Argentine players had previously featured in a Davis Cup tie. Although the 2016 champions boast eight players in the ATP top 100, they travelled to South Korea with only one, Tirante.
South Korea will now face the winner of the tie between India and the Netherlands in the second round, with a place in the Davis Cup Final 8 at stake.
In Bengaluru, India led the Netherlands 2–1 after Yuki Bhambri and Dhakshineswar Suresh edged Sander Arends and David Pel in two tie-breaks, winning 7–6 (7–0), 3–6, 7–6 (7–1).
In Tatabanya, Christian Harrison and Austin Krajicek secured the decisive point for the United States with a 6–4, 3–6, 6–3 win over Fabian Marozsan and Zsombor Piros. Harrison said he enjoyed his Davis Cup debut so much he had almost forgotten about the Australian Open.
Belgium also progressed after Sander Gille and Joran Vliegen beat Bulgaria’s Alexander Donski and Pyotr Nesterov 7–6 (7–5), 7–6 (7–3) in Plovdiv.
In France, Benjamin Bonzi and Pierre-Hugues Herbert put the hosts 2–1 ahead against Slovakia, while Ecuador took a 2–0 lead over 28-time champions Australia in Quito.
Germany, Austria, Chile, Croatia, Britain and Canada had already secured their places in the second round earlier in the weekend.