Coventry City returned to Wembley 30 years on from their finest hour and upset the odds again, winning the 2017 Checkatrade Trophy to go with the 1987 FA Cup after Mark Robins’s side did just enough to hold off Oxford United.

Those 30 years have not been kind to Coventry. With the club bottom of League One and 13 points from safety, the fourth tier beckons for the first time since 1958-59 and the tailspin under nine years of Sisu ownership shows no sign of abating. But goals from Gaël Bigirimana and George Thomas, coupled with a fierce rearguard effort once Liam Sercombe had pulled one back for United, were enough to ensure this miserable season holds at least one memory worth cherishing.

“It means everything to the supporters,” said Robins, whose club brought the bulk of the 74,434 in attendance – the highest for this final since 2000, its last year at the old Wembley.

“It’s 30 years since they’ve been to Wembley and it was really important for us as a football club to show the world that we are still alive and kicking. It gives everybody a reminder that we have a really good fanbase and there’s so much potential at this place. We have to harness it and move forward with it. Whatever that looks like in the future, we have to make sure it’s the best it can be.”

Their immediate future certainly seems to lie in League Two. Beyond that no one can say, though many fans fear the plummet under Sisu will not bottom out in the lowest tier of the Football League and the only thing that is certain is uncertainty – they have no stadium agreement at the Ricoh Arena beyond next season and their academy, which produced their man‑of‑the‑match Thomas, may be homeless before that.

Just for a moment, though, those concerns took a place on the back burner. Indeed it was over an hour before the first significant “Sisu out” chants could be discerned in the Coventry end.

John Sillett, who, with George Curtis, managed the Cup-winning side of 1987, appeared on the pitch pre-match to invoke the spirit of Houchen, Kilcline and co. And there was a pleasingly retro 80s feel for both these finalists – while City had not played at the national stadium since the Charity Shield in 1987, Oxford’s own Wembley moment came a year earlier with their League Cup win against Queens Park Rangers in 1986. Unlike City, Oxford have been occasional visitors since, most recently in last season’s Football League Trophy final.

They had taken the lead against Barnsley in that game before slipping to defeat but this time, after a scrappy opening, Michael Appleton’s side were soon on the back foot. Stuart Beavon’s volley from Jordan Willis’s cross was blocked but Bigirimana, who celebrated the birth of his daughter Eden on Saturday, swept home the loose ball to give City the lead.

Thereafter Oxford enjoyed the lion’s share of possession without creating a great deal apart from an optimistic penalty shout on the half-hour as Kane Hemmings tumbled under Chris Stokes’s challenge. Coventry threatened sporadically on the break but were worth their half-time lead.

That lead doubled nine minutes after the interval. Thomas, who had already forced Simon Eastwood into a superb save after a quick corner, this time gave him no chance, controlling Kyel Reid’s cross on the edge of the area before sending a low volley whistling into the bottom corner.

That goal left their opponents deflated. “Normally we deal with disappointment within games pretty well, we clear our heads pretty quickly,” Appleton said of his team’s lacklustre response to the concession. “I thought it took too long today.”

United, who still harbour slim hopes of a play-off campaign, did finally rouse themselves and Sercombe’s low shot somehow squeezed through a crowded area to give Oxford hope with 15 minutes to go. Rob Hall should have brought them level three minutes later but shot straight at Lee Burge when clean through and an almighty scramble deep into stoppage time somehow ended with the ball in the hands of Burge with two Oxford players grounded in despair in the six-yard box.

Relegation may be looming – “We are hoping that we can pick up results and stave off that for as long as we can,” Robins said – but it is not a bad way for him to start after becoming City’s fourth manager of the season under a month ago. “That surpasses everything,” he said. “The experience was just phenomenal. I’ve never experienced that as a manager before, I’ve experienced winning at Wembley as a player before, and that was one of the best footballing experiences I’ve ever had.”