Tomas Berdych continued his fine form in the build-up to next week's French Open as he beat Carlos Berlocq to give the Czech Republic the lead over Argentina in the World Team Cup in Dusseldorf.
Berdych was pressed by the world number 37, who took the second set of their Red Group clash on the tie-break, but he rallied to close out a 6-1 6-7 (7/2) 6-3 win and boost his nation's hopes of a place in the final.
Serbia's hopes of qualifying from Blue Group were also given a lift as Viktor Troicki won the opening rubber against Germany's Florian Mayer 7-6 (8/6) 6-3, ahead of tomorrow's decisive singles and doubles matches.
Also in Blue Group, Ivan Dodig gave Croatia a narrow lead against Russia after holding off Igor Kunitsyn 7-6 (7/0) 6-4 in their match lasting one hour and 40 minutes.
In Red Group, the United States edged a 2-1 win over Japan with Ryan Harrison beating Tatsuma Ito and Harrison and James Blake defeating Ito and Bumpei Sato, before Go Soeda scored a consolation 7-5 7-6 (7/4) win over Andy Roddick.