Andy Murray had to dig deep to ensure Great Britain made a winning start in their Davis Cup round-robin tie against Switzerland in Manchester.
With Britain aiming for a place in November’s eight-team knockout stage, Murray edged past Swiss debutant Leandro Riedi 6-7 (7-9) 6-4 6-4.
Cameron Norrie can seal victory by beating Stan Wawrinka later on Friday.
If Norrie loses, Dan Evans and Neal Skupski can secure a second straight GB win by taking the deciding doubles.
Even if Britain beat the Swiss in the best-of-three tie, they cannot secure qualification until Sunday’s final tie against France.
Four nations – Britain, Australia, France and Switzerland – are playing in the group stage event held at Manchester’s AO Arena.
They all play each other once in a round-robin format, with the top two countries going through to the knockout stage – known as the ‘Final Eight’ – in Malaga in November.
“It’s incredible to get through that one – it easily could have gone the other way,” said Murray, who helped Britain win the Davis Cup in 2015.
“It was ridiculous the shots he was pulling off, some amazing returning.”
Britain clinched victory in Wednesday’s opening tie against Australia when debutant Jack Draper and Dan Evans – picked ahead of Murray and Norrie based on their current form – won their singles matches.
In another interesting move on Friday, British captain Leon Smith decided to go with Murray and Norrie against the Swiss as he utilised the whole of a talented squad.
The majority of the home crowd, which watched Murray play in Manchester for the first time since 2004, probably did not expect the former world number one to be pushed so hard by 21-year-old Riedi.
But, as they have seen so often in the past, Murray dug deep into all of his vast physical and mental reserves to secure the victory.
While he was far from his best, the three-time Grand Slam champion had enough quality and experience to come through on what he then revealed was the day of his grandmother’s funeral.
Overcome with emotion, a tearful Murray said: “I’m sorry to my family I’m not able to be there. Gran this one us for you.”