Millwall assistant manager Joe Gallen described staying in the npower Championship as "a fantastic achievement" after the Londoners avoided relegation despite slipping to a 1-0 defeat at Derby on the final day of the season.
The Lions could have guaranteed safety with a point but instead were tamed by Conor Sammon's late goal at Pride Park, only to be rescued by Huddersfield's equaliser at home to Barnsley and Crystal Palace's late fightback against Peterborough - with Posh ultimately joining Wolves and Bristol City in the relegation zone.
Millwall gave a nervy performance and had rarely threatened when Sammon produced a fine left-foot finish from Jamie Ward's cunning through ball five minutes from time, but Gallen was adamant that retaining their Championship status constituted a good season.
"The plan was to come here and at least get a point; unfortunately we've relied on other teams," he said.
"It's a great achievement to stay in the division - we're one of the smaller clubs in the Championship. We haven't lost a London derby this season and that's something important to our fans."
The win gave Nigel Clough his first top-10 finish in the division and the Derby manager was optimistic about his side's chances of promotion next season.
"It's lovely to finish 10th in the league," he said. "We know we've improved our performances this season.
"Our aim next season is to get four strikers of similar quality if we can, so if it's not quite working for the two playing we've got options. It's been too much this season; Conor's had to play 40-odd games.
"We're optimistic - we see what we've got out there now and it's not a team that's going to need breaking up in the next few seasons. We might only have one or two players over 30 going into next season.
"We just need a little bit more experience, we certainly need a centre-half as that's the only two we've got out there, and we need a centre-forward."