AFP/ Glasgow

Andy Murray fired Great Britain into a first Davis Cup final in 37 years after his victory over Bernard Tomic handed his side an unassailable 3-1 lead in their World Group semi-final clash against Australia.

The World number three secured a final showdown against Belgium or Argentina in November with a 7-5, 6-3, 6-2 win over Bernard Tomic in the first reverse singles rubber on Sunday to clinch the best-of-five tie after playing three days in succession at the Emirates Arena in Glasgow.

The 28-year-old's 25th win from 27 Davis Cup singles matches, which took under two hours, secured a first victory over old rivals Australia since 1978.

It puts nine-times winners Britain on the verge of an historic first title triumph since 1936 when Fred Perry and Bunny Austin sealed a 3-2 victory over Australia at Wimbledon.

Britain have now become the first nation to defeat the three other Grand Slam nations in consecutive ties since they beat Australia, USA and France en route to winning the Davis Cup in 1933.

It is a remarkable turnaround for a British team that have risen from being on the verge of relegation to Zone Group III, the lowest level of the competition, in 2010, to being World Group finalists in 2015.

Murray, who won both singles matches and the doubles with brother Jamie, is now looking to become only the fourth player ever to win the Davis Cup, Olympic gold and multiple Grand Slams.

Australia were looking to reach their first Davis Cup final since winning the trophy for a 28th time in 2003,

Australian captain Wally Masur had hinted on Saturday he was thinking of throwing veteran Lleyton Hewitt in against the two-time Grand Slam winner to see if the former world number one could deliver a famous victory.

However, he opted to keep faith with world number 23 Tomic, who had delivered success in his opening singles encounter with Dan Evans on Friday.

Murray opened the tie with an ace and it set the tone for the early part of the set as some incredible returns saw him break Tomic in the fourth game.

Murray survived one break point as he was serving for the set at 5-3, but a double fault followed by an unforced error allowed Tomic to break back. However, Murray recovered and with Tomic serving to send the set into a tie-break, the Brit found himself with three set points.

The 22-year-old Australian saved the first two but a brilliant drop shot left Tomic stranded and sealed the first set for Murray.

The two-time Grand Slam winner at times appeared unplayable in the second set. After breaking the Tomic serve early on, Murray held his service game to love to seal the second set 6-3.

With the finishing line in sight, Murray found some extra reserves to step up a gear in the third set and twice broke Tomic to serve for the match with his opponent sending a return wide to seal the win and send the home crowd wide.