Juan Martin Del Potro rallied from two sets down to beat Marin Cilic 6-7 (4), 2-6, 7-5, 6-4, 6-3 as Argentina drew level at 2-2 with Croatia in the Davis Cup final on Sunday.
The best-of-five series will now be decided in the second reverse singles played later Sunday between Croatia’s Ivo Karlovic and Argentina’s Federico Delbonis.
Croatia was leading 2-1 in the series after winning the doubles on Saturday.
Only twice since the World Group Davis Cup format was introduced in 1981 has a team come back from 2-1 down in the final.
Argentina is targeting its first Davis Cup title after playing in four finals. Croatia won in 2005.