There will be one man with a special interest in the outcome of the FA Cup fifth-round tie between Manchester United and Arsenal at Old Trafford.

Having served both clubs with distinction, Frank Stapleton could be forgiven for suffering from split loyalties this evening, but it was as an Arsenal player in the 1979 Cup Final against United that the former Ireland striker experienced one of the greatest adrenalin rushes of his career.

Arsenal were 2-0 up with five minutes remaining and on course to erase the memory of their defeat by Ipswich Town in the previous year’s final. “We were coasting,” Stapleton, who had scored Arsenal’s second goal, recalled. Not for long.

Within three minutes, United had drawn level through Gordon McQueen and a fine solo goal from Sammy McIlroy.

“It was an unbelievable turnaround of emotions,” Stapleton said. “They had almost resigned themselves to losing but then out of the blue they nicked a goal back, we panicked, and then Sammy made it 2-2.

“Suddenly you remind yourself that you lost in the final the previous year and all that comes into your mind is negativity. I was thinking, ‘Oh, no, we’re going to lose again’ and had this horrible feeling in the pit of my stomach.”

It was only when Stapleton moved to Old Trafford two years later that he discovered how confident United’s players had been that they would win the match before Alan Sunderland claimed the last-gasp goal for Arsenal.

“Speaking to many of the lads after I joined United, there was no doubt in their minds that they were going to go on and win,” Stapleton said. “We were on our knees, but when Alan scored I knew just how they felt because we’d felt the same a minute earlier.

“That’s why the FA Cup gets me going more than any other competition because it continually throws up these kind of situations.”

Stapleton, who also won the competition with United in 1983 and 1985, believes that victory for Sir Alex Ferguson’s team today could prove a psychological blow to Arsenal’s title hopes. “I actually feel that United are underdogs for the match, even with it being at Old Trafford, but I think they might just edge it because they’ve got more to prove after a couple of bad results,” he said.