World number 10 Juan Martin del Potro shrugged off a bout of nausea to cruise past Ivo Karlovic 6-2, 7-6 (7), 6-1 and pull Argentina level 1-1 with Croatia in their Davis Cup quarterfinal on Friday.
Del Potro had been reported to have suffered from vomiting in the morning but he showed few ill effects to keep his country's campaign on track.
Marin Cilic had given Croatia, the 2005 champions, a winning start when he beat David Nalbandian 5-7, 6-4, 4-6, 7-6 (2), 6-3 in a five-hour epic scarred by 241 unforced errors.
USA take lead
Roquebrune, France: Bob and Mike Bryan defeated Julien Benneteau and Michael Llodra 6-4, 6-4, 7-6 (4) on Saturday to give USA a 2-1 lead over France in their Davis Cup quarterfinal.
The Bryans, the top-ranked doubles pairing, have not lost a Davis Cup match since 2008.