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 on Friday 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.”

In Liege, holders Switzerland, missing big guns Roger Federer and Stan Wawrinka, were all square 1-1 with Belgium.

Unheralded Henri Laaksonen gave the defending champions the perfect start with a surprise 1-6 6-7 (6-8) 6-4 6-0 6-2 defeat of Ruben Bemelmans.

Steve Darcis then had the Belgians up and running with a one-sided win over Michael Lammer.

Beaten 2014 finalists France were in control of their clash with Germany after wins for Gilles Simon and Gael Monfils over Jan-Lennard Struff and Philipp Kohlschreiber respectively.

Australia were in a similarly comfortable position in Ostrava against the Czech Republic.

Teenager Thanasi Kokkinakis stunned the Czech’s top player Lukas Rosol 4-6 2-6 7-5 7-5 6-3, with Bernard Tomic then seeing off Jiri Vesely 6-4 6-3 7-6 (7-5).

In Almaty, Kazakhstan and Italy were level at 1-1.

The two other ties are between Canada and Japan, and Argentina against Brazil.