The Shrimps clinched their place in League One for next season after defeating Newport County AFC 1-0 at Wembley.
Carlos Mendes Gomes netted the only goal with a penalty early in the second period of extra time, settling a tense and energy-sapping afternoon.
Lavelle became the third Morecambe skipper to lead his side to victory at the national stadium, following in the footsteps of Jim Bentley and Bob Baldwin, who passed away earlier this season.
He is also one of the survivors from the Morecambe team who beat the drop into the National League on the last day against Coventry City in 2018.
“It’s so hard to put it into words, I can’t explain the relief,” Lavelle said.
“It’s unbelievable, the turnaround this club has had is phenomenal.
“Extra time wasn’t ideal for the legs but Carlos stepping up (for the penalty), I never doubted him. He took penalties yesterday in training and was unbelievable.
“Even though they were putting pressure on at the end, I didn’t think they were going to score.
“We defended so well and for this club to be going into League One is unheard of.
“There’s no reason why we can’t do well in League One, we will enjoy it now and then go again next season.”
Lavelle had endured a difficult time when the Shrimps met Newport earlier in the year.
He was sent off in the 3-1 defeat but helped to keep the opposition quiet on this occasion.
“It’s a good time to have a decent game!” he joked.
“We got a clean sheet and we couldn’t ask for any more.
“Me and Nat (Knight-Percival) had a good partnership at the back, Yann Songo’o and the two full-backs (Ryan Cooney and Liam Gibson) were unbelievable.
“It wasn’t the best game to watch but, defensively, we were unbelievable.”
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