GLASGOW - Andy and Jamie Murray moved Great Britain to the verge of a first Davis Cup final since 1978 after defeating Australia's Lleyton Hewitt and Sam Groth in an epic doubles clash in their semi-final on Saturday.

World number three Andy and older brother Jamie recovered from a set down to secure a thrilling 4-6, 6-3, 6-4, 6-7 (6/8), 6-4 victory in a gruelling four-hour rubber. Victory gave the home side a 2-1 lead and it means Andy Murray can now clinch the tie for Great Britain in Sunday's first reverse singles as they attempt to win the competition for the first time since 1936.

The 28-year-old will secure a final showdown against either Belgium or Argentina in November if he defeats scheduled opponent Bernard Tomic. If he loses, British world number 300 Dan Evans is due to face teenager Thanasi Kokkinakis in what would be the decisive second reverse singles.

"It was an incredible match and we had to come back from the disappointment of losing the fourth set," two-time Grand Slam winner Andy said. "We stuck together like brothers should and managed to come up with enough good returns. It was as emotionally draining as much as it was physically."

Australia, 28-times winners of the tournament, had been looking to reach their first final since 2003 but are now on the brink of a first defeat against old rivals Britain since 1978. "Davis Cup doubles over five sets can sometimes only rely on one or two points," said Hewitt, who is featuring in his final Davis Cup campaign. "Doubles is always crucial but there is still two matches to go and we have to come up with the best plan to win those matches and give ourselves an opportunity to go through to the final."

With the tie delicately balanced after Friday's singles, British captain Leon Smith put Andy alongside Jamie instead of Dominic Inglot as he opted for the pairing who secured a four-set victory over Nicolas Mahut and Jo-Wilfried Tsonga in the quarter-final against France.

Australia captain Wally Masur kept faith with veteran Hewitt and Groth after the pair had helped to inspire a remarkable comeback from 2-0 down against Kazakhstan in the previous round. And it was the Australians who made the breakthrough first as the mighty returns of Groth helped them to break Jamie Murray's serve in the fifth game.

The Australian pairing then survived three break points as Groth served to take the set 6-4. It was the older Murray sibling, who missed out on Grand Slam glory in both the Wimbledon and US Open doubles finals this year, that looked more comfortable in his familiar surroundings of doubles tennis as he helped the British to a break in the sixth game of the second set. He bisected the Australians with a clinical volley following some terrific net play on their way to a 6-3 victory.

Their good work seemed to come undone in the second game of the following set as Australia immediately broke to race into a 4-1 lead. However, the Murrays produced a remarkable comeback as they won the following five games in a row to take the set 6-4.

Hewitt and Groth looked dejected but they recovered to break in the second game of the fourth as Jamie Murray made some uncharacteristic errors. Their joy was short-lived, however, as Britain broke back immediately as the set headed into a tie break where the Australians survived a match point.

There was more drama in the decisive fifth set as a fine Andy Murray return earned his side two match points and they sealed victory when Groth fired a volley over the baseline. "We had a chance at 6-5 to close it out and then the tie break as well but they came out with some great shots," said Jamie Murray. "But we kept fighting hard and didn't panic and we're so pleased to get the win for the team."