Straight-sets wins for Borna Coric and Marin Cilic put Croatia firmly in control of their Davis Cup final clash with France in Lille.
French captain Yannick Noah gambled by leaving out his top-ranked player Lucas Pouille in favour of Jeremy Chardy and Jo-Wilfried Tsonga for the opening singles rubbers but it did not pay off.
France are looking to win back-to-back titles for the first time since the early 1930s but now must come out on top in the remaining three matches over the next two days.
That appears highly unlikely based on the respective performances on Friday on the indoor clay surface at the Stade Pierre Mauroy, with Croatia one step away from emulating their 2005 triumph.
22-year-old Coric continued his breakthrough 2018 by defeating Chardy 6-2 7-5 6-4 before Cilic claimed a 6-3 7-5 6-4 victory over Tsonga.
Noah had no doubt hoped the occasion would inspire Tsonga, ranked down at 259 following knee surgery, to find some vintage form but he was no match for world number seven Cilic.
France at least have a good chance of pushing the tie into Sunday, with Nicolas Mahut and Pierre-Hugues Herbert narrow favourites for Saturday's doubles rubber against Mate Pavic and Ivan Dodig.
