Croatia's Marin Cilic and Ivan Dodig won the doubles encounter against Argentine doubles pair Juan Martin del Potro and Leonardo Mayer 7-6 (7/2), 7-6 (7/4), 6-3 on Saturday to give Croatia a crucial 2-1 lead in the Davis Cup final.
Former US Open champion Cilic had earlier put Croatia 1-0 up by winning Friday's opening singles rubber against Federico Delbonis before Del Potro levelled for Argentina with a four-set win over Ivo Karlovic.
Both Cilic and Del Potro were drafted in for Saturday's doubles with the former teaming up with Dodig to claim the first two sets in a tie-break before wrapping up victory after Mayer dropped serve at 3-2 down in the third. "The atmosphere was absolutely fantastic as our fans carried us throughout the contest," said Cilic.
Dodig added: "This is a once in a lifetime experience and I have to thank the fans for creating a fantastic atmosphere. "We will be rooting for Marin to finish the job ."
Olympic silver medallist Del Potro, who has bounced back after two injury-ravaged seasons, must beat sixth-ranked Cilic in Sunday's reverse singles to keep alive Argentine hopes of a first Davis Cup title.
"Del Potro is an incredibly good player but I am confident I have enough left in the tank to finish the job," added Cilic.However, should Del Potro extend the tie 37-year-old Karlovic the oldest player to feature in a Davis Cup singles match since 43-year-old Australian Norman Brookes in 1920 -- and Delbonis would then face off in the deciding rubber.
Croatia defeated Slovakia in 2005 for the country's only Davis Cup title, while Argentina -- beaten by Spain in both 2008 and 2011 -- have finished runners-up four times.