Dallaglio, 35, was given a standing ovation when he was replaced in the 68th minute, but was keen to share the spotlight with his team-mates.
"This was not about me, it was a wonderful squad effort," he said.
"We were 10th in the table around Christmas time, so this is probably our greatest achievement."
"We have had some great days in the last few years but given where we were after the World Cup this is probably our greatest achievement.
"We played a mighty opponent today in Leicester and we always knew it was going to be tough. They came back at us but we held on and performed heroically."
Humble words from the departing Dallaglio, who will now have time to sit back and reflect on an amazing career that saw him become the second-most capped Englishman of all time.
He won 85 international caps for his country, is one of only two players to have won both the World Cup and the Sevens World Cup, he's claimed a Grand Slam with England, and also went on three Lions tours. With his beloved Wasps he has won two Heineken Cups and now five English titles.
A fitting tribute to a legend of England, Wasps, and world rugby.