EUROPE'S come-from-behind victory in the 2012 Ryder Cup has passed into posterity as the Miracle of Medinah and if Great Britain can overhaul a 2-0 Davis Cup deficit against Argentina it should perhaps become known as the Great Escape of Glasgow. While the giant presence of Juan Martin Del Potro still guarantees the South Americans the whip hand going into the final day of this semi-final tie, all of sport's halcyon comebacks had to start somewhere too and Andy and Jamie Murray's 6-1, 3-6, 6-4, 6-4 victory against Del Potro and Leonardo Mayer yesterday will at least have planted the first seeds of doubt in Argentine minds.

The world No 2 surrendered his unbeaten record in Davis Cup singles rubbers on home soil on Friday but he and his brother, on the same weekend their grandfather Gordon was laid to rest, were in no mood to hand away their perfect run in this competition. Another illustration of the famed resilience which runs in this family kept Britain's hopes of retaining their trophy on a simmer at 2-1 down, not least because of the eccentric decision by Argentina captain Daniel Orsanic to pitch his talisman from Tandil into action for a second successive day. He may now also have to take on a fresh Dan Evans, or perhaps Kyle Edmund, with more than eight hours of tennis in his body.

While Andy Murray must dispose of Guido Pella for the tie to get that far, the giant Argentine was complaining last night of pains in his "legs, wrist, back, shoulders" and insisting he couldn't take a risk with his re-found fitness.

"I didn't expect to play eight hours in two days and it is enough at this moment in my comeback," said Del Potro, who could potentially be replaced by Federico Delbonis or Mayer. "I am trying to do my comeback slowly, but I did a big effort during the week and hopefully I can finish the week healthy. I could be at risk if I had to play a match like yesterday."

The British camp was certainly a more upbeat place than it was on Friday night. "Being 2-1 down is incredibly tough position to be in, but we are closer than we were in the morning and I still think we can get it back," said Andy. "I'll give it my best effort tomorrow, whether I win or not I don't know. But it will make it interesting if it goes to the fifth rubber."

Captain Leon Smith said he felt the Murray brothers had given everyone a lift. "We’re still alive in the tie," he said. "We start with Andy’s match and support him as much as possible - and it he gets us the point, then it gets interesting."

If it was appropriate, considering the state of the tie, that the Red Hot Chilli Pipers' pre-match set should include the Journey anthem 'Don't Stop Believing', Orsanic was clearly determined to strangle home hopes of a resurgence at birth. While the Murray brothers had a 58-match body of work to reflect upon as a pairing, the form book offered little in the way of clues about the effectiveness of Del Potro and Mayer.

This was just their fourth match together, including a humdrum 2004 outing back in Buenos Aires. They had one match win to their name, in Indian Wells this year, taking just 57 minutes to get rid of Ivan Dodig and Marcelo Melo. But that was a serious scalp for an ad hoc team to take, considering the latter held Jamie Murray's occasional spot as No 1 in doubles at the time. Alongside Maximo Gonzalez in Rio, Del Potro had managed to win one more round at the Olympics than the Murray brothers could.

A typically rousing welcome was the precursor to these two exiled products of Dunblane starting this match like a train, with the elder sibling, his third major win tucked neatly into his kit bag, the senior partner. He swarmed all over the net, using his instinct and reactions to effect, as the Scottish pairing raced into a 5-0 lead before a shell-shocked Mayer could find enough poise to hold serve for the first time. Any respite was only temporary. Del Potro netted on set point and Britain had made the first step of their recovery.

Jamie's level was imperious throughout, and Andy said afterwards that it had needed to be. One strangely unconvincing service game from Andy which contained two double faults and couple of mis-steps at the net handed Argentina the early service break which saw them level matters, and the visitors were a break to the good in the third set too, the Tannoy man slipping on 'Bad Moon Rising'.

These extraordinary Scottish brothers ignored the omens and made their own luck. Instantly, they were back on serve, and the decibel level went through the roof when the world No 2 glimpsed Mayer anticipating cross court, and spanked a Del Potro second serve return down the line for a two sets to one lead.

Del Potro appeared to be mentally preparing for day three by the time one last Andy volley after some rat-a-tat-tat stuff at the net won the day, Jamie appearing almost overwhelmed with emotion afterwards.

“It’s been a tough week for us," he said. "We had to try to park it for the afternoon and focus on what we needed to do. It’s one of those things you have to go through in life. It’s not easy but I think we did a good job."