Manager Stephen Kenny saw a good night for Dunfermline tarnished by a late red card for Scott Wilson.
Kenny saw his side demolish relegation rivals Motherwell
"We did well but I'm disappointed that we took our foot off the gas against 10 men and got sloppy," he told BBC Sport after the 4-1 victory over Motherwell.
"We conceded a goal and got a man sent off because we were casual at 3-0.
"We were brilliant in the first half and I'm very pleased with the players but we were eight hours without conceding and now we've lost Scott."
Bottom of the table Dunfermline now trail St Mirren by just one point, with two games of the campaign remaining.
"We've got a very hard game up at Inverness next and we have to make sure we prepare well," added Kenny.