Italy took a 2-1 lead over Argentina in the Davis Cup first round by winning a four-set doubles on Saturday.
Fabio Fognini and Simone Bolelli defeated Eduardo Schwank and Horacio Zeballos 6-7 (6), 7-6 (8), 7-6 (3), 6-4 in a four-hour match on outdoor clay.
Italy needs to win one of the reverse singles on Sunday to wrap it up, with Fognini expected to face Carlos Berlocq and Andreas Seppi against Juan Monaco.
Italy has won the Davis Cup once, and Argentina has been a runner-up four times.
Argentina was without its top player Juan Martin del Potro, who has skipped the cup to concentrate on the ATP tour.