Doubles pair Jamie Murray and Joe Salisbury needed to win their match against Grigor Dimitrov and Alexandar Lazarov to secure overall victory.
But after the first two sets were shared following tie-breaks – 7-6 (7-5), 6-7 (2-7) – it then came down to a match tie-break that the Bulgarian pair took 11-9 in the early hours of the morning in Australia.
The match went down to the final rubber after British No 1 Dan Evans surrendered a one-set lead to lose 2-6, 6-4, 6-1 to US Open semi-finalist Dimitrov in the second singles match.
Cameron Norrie had given his country the perfect start by overcoming Dimitar Kuzmanov 6-2, 3-6, 6-2.
The new 24-nation tournament features six groups of four teams. Each country plays three round-robin ties which are comprised of two singles matches and one doubles.
In the other Group C match, a Belgium team comprised of Steve Darcis, David Goffin and doubles pair Sander Gille and Joran Vliegen defeated Moldova 3-0. Tournament organisers apologised to Moldova after mistakenly playing the Romanian national anthem before the match.
Hosts Australia enjoyed a successful start by whitewashing Germany 3-0. Nick Kyrgios and Alex De Minaur each won singles matches to give their team an unassailable lead, defeating Jan Lennard-Struff and world No 7 Alexander Zverev respectively.
Kyrgios served 20 aces in a win that cost him $4,000 in local currency. Kyrgios, so often considered the bad boy of tennis for his emotional behaviour and outbursts, promised to donate A$200 for every ace he serves this month to go toward the recovery effort from the wildfires that have devastated parts of Australia, leaving at least 19 people dead and 1,400 homes destroyed.
He opened and closed his 6-4, 7-6 (7-4) win over Struff in Brisbane with booming serves – including a second-service ace to close it out.
Kyrgios devised the cash for aces idea earlier in the week, and inspired other fundraising efforts from other players and from organisers of the ATP Cup and the Australian Open. He said he was motivated by the plight of people struggling in parts of the country impacted by the fires, including his hometown of Canberra.
“It’s tough,” Kyrgios said, choking back tears. “[The money raised] is going to the families, fire fighters, animals, everyone who is losing homes, losing family – it’s a real thing. It’s bigger than tennis, you know.”
Canada won the other Group G encounter in Brisbane, beating Greece 3-0. In the Group D matches played in Perth, the United States were beaten 2-1 by Norway, while Russia defeated Italy 3-0.