Paris - Serbia's world No 1 Novak Djokovic and Great Britain's Andy Murray breezed to comfortable wins as Davis Cup World Group first round action began in dramatic style on Friday.
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 number five dominating Donald Young 6-1, 6-1, 4-6, 6-2.Ward in thriller
The packed house in Murray's hometown were treated to some gripping Davis Cup theatre as James Ward pulled 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 Isner.
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 after the world number 20 hit a backhand into the net.
After four hours and 57 minutes 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."
Over in Liege, 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 got the Belgians up and running with a one-sided win over Michael Lammer.
The winner of that tie will face either Canada or Japan, who were all square at 1-1 after wins for Milos Raonic and Kei Nishikori in Vancouver.
Canadian number one Raonic, ranked sixth in the world, got the hosts off to a smooth start with a 6-2, 6-1, 6-2 victory over 85th-ranked Tatsuma Ito.
Raonic fired 17 aces and never faced a break point.
Nishikori, the 2014 US Open runner-up, ranked fourth in the world, found the going a bit tougher against Vasek Pospisil, but leveled the tie with a 6-4, 7-6 (7/5), 6-3 win in two hours and 19 minutes.
The split sets the stage for a key showdown between Raonic and Nishikori in Sunday's reverse singles.
Beaten 2014 finalists France were fully in control of their clash with Germany after wins for Gilles Simon and Gael Monfils over Jan-Lennard Struff and Philipp Kohlschreiber respectively.Kokkinakis shocks Rosol
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).
"I hung in there, kept digging. I was a break down in the fifth but I felt good. I'm so happy with that win," said Kokkinakis.
"When my back's against the wall I usually can find a way to get it done," he added.
In Almaty, Kazakhstan and Italy were level at 1-1, as were Argentina and Brazil in Buenos Aires.Results on Friday in the Davis Cup World Group first round ties:
BRITAIN 2 UNITED STATES 0
Andy Murray (GBR) bt Donald Young (USA) 6-1, 6-1, 4-6, 6-2
James Ward (GBR) bt John Isner (USA) 6-7 (4/7) 5-7 6-3 7-6 (7/3) 15-13
SERBIA 2 CROATIA 0
Novak Djokovic (SRB) bt Mate Delic (CRO) 6-3, 6-2, 6-4
Viktor Troicki (SRB) bt Borna Coric (CRO) 4-6, 1-6, 6-3, 6-2, 6-1
KAZAKHSTAN 1 ITALY 1
Mikhail Kukushkin (KAZ) bt Simone Bolelli (ITA) 7-6 (8/6), 6-1, 6-2
Andreas Seppi (ITA) bt Andrey Golubev (KAZ) 6-3, 6-3, 6-7 (5/7), 6-2
BELGIUM 1 SWITZERLAND 1
Henri Laaksonen (SUI) bt Ruben Bemelmans (BEL) 1-6, 6-7 (6/8), 6-4, 6-0, 6-2
Steve Darcis (BEL) bt Michael Lammer (SUI) 6-3, 6-1, 6-3
GERMANY 0 FRANCE 2
Gilles Simon (FRA) bt Jan-Lennard Struff (GER) 7-6 (7/4), 2-6, 6-7 (1/7), 6-2, 10-8
Gal Monfils (FRA) bt Philipp Kohlschreiber (GER) 6-4, 7-5, 7-6 (7/4)
CZECH REPUBLIC 0 AUSTRALIA 2
Thanasi Kokkinakis (AUS) bt Lukas Rosol (CZE) 4-6, 2-6, 7-5, 7-5, 6-3
Bernard Tomic (AUS) bt Jiri Vesely (CZE) 6-4, 6-3, 7-6 (7/5)
ARGENTINA 1 BRAZIL 1
Joao Souza (BRA) bt Carlos Berlocq (ARG) 6-4, 3-6, 5-7, 6-3, 6-2
Leonardo Mayer (ARG) bt Thomaz Bellucci (BRA) 6-4, 6-3, 1-6, 6-3
CANADA 1 JAPAN 1
Milos Raonic (CAN) bt Tatsuma Ito (JPN) 6-2, 6-1, 6-2
Kei Nishikori (JPN) bt Vasek Pospisil (CAN) 6-4, 7-6 (7/5), 6-3