The effort produced was evident as the seconds ticked down towards the final whistle.
Players were hobbling around the pitch, while others dropped to the turf with cramp as a gruelling 120 minutes came to an end.
But it was all worth it for Pompey’s academy players as they secured an FA Youth Cup first round victory over Gillingham.
Matt Mayes cancelled out Leroy Hlabi’s early penalty at Priestfield Stadium before grabbing the winner in extra-time.
And Mikey Harris was thrilled with the way his side coped with falling behind to eventually seal their progress.
The lead professional development phase coach said: “It was a bit of a disastrous start, but credit to the boys because they responded really well.
“Their body language, attitude and application remained the same, and we got back on level terms through a brave goal from Matt.
"You could sense the nerves from some of the boys, but they showed a lot of character and I’m really pleased for them."
“We did make it a bit difficult at times, but Gillingham were very competitive and it was a very entertaining match that was a good advert for youth football.
“After the initial setback we felt that we had a strong shape and the ability to control the ball, although we didn’t do that as much as we would like.
“You could sense the nerves from some of the boys, but they showed a lot of character and I’m really pleased for them.
“All the subs who came on played their part and it was a real squad effort, so now we’re looking forward to the next test.”
Pompey will now face a home test against Lewes in November, with a date for the tie still to be arranged.
Harris said: “We’re delighted to be through to the next round and we’ve got a game at Fratton Park to look forward to.
“That’ll be the highlight of some of their careers to date and I’m sure the fans will come out in their numbers to support the boys.”