Serbia's world No.1 Novak Djokovic and Britain's Andy Murray breezed to comfortable wins as Davis Cup World Group first-round action began in dramatic style.
Djokovic dispatched Mate Delic in three sets and Viktor Troicki came through in five against Borna Coric to put 2010 champions Serbia 2-0 up against a Croatia team struggling without US Open champion Marin Cilic.
"Mate is a talented player with a lot of potential to reach the top in the tennis world, but I'm happy with my performance and that I managed to win," Djokovic said.
Murray, like Djokovic, opened for the British against the United States in Glasgow, the world No.5 dominating Donald Young 6-1 6-1 4-6 6-2.
The packed house in Murray's home town were then watched James Ward pull off a thrilling 6-7 (4-7) 5-7 6-3 7-6 (7-3) 15-13 win over John Isner to make it 2-0 to the hosts.
Ward, ranked 111 in the world, looked destined for defeat as he lost the first two sets against the big-serving American.
Isner, the man who triumphed in the longest tennis match in history at Wimbledon in 2010, saved five match points in an epic final set, but Ward eventually prevailed over the world No.20.
After just under five hours of action, Ward said: "That was by far the best atmosphere I've experienced in the Davis Cup.
"I'd prefer not to play these five-set matches but the crowd were incredible and really helped me through."