The 24-year-old joined Everton earlier this summer for a fee of £23.6m, thus ending his long association with the Dutch giants.
Klaassen came through the much vaunted Ajax academy and went on to make 163 appearances for the club, scoring 49 goals in the process.
The midfielder's all-action displays endeared him to the fans at the Amsterdam Arena and they were delighted to see the player, who won three Eredivisie titles during his time at the club, return.
The Dutch international played 55 minutes of Everton's win over Bournemouth on Saturday but was granted permission to return to his homeland to watch his former side as they beat Vitesse Arnhem 2-0.
The player was paraded around the pitch before the game, before fans held aloft a banner thanking him for his contributions to the club.
The fans were reminded of some of thoses contributions by an 85-second long compilation of some of Klaassen's goals.
He's all grown up now! #DavyBedankt pic.twitter.com/IkRT9dTMAw
— AFC Ajax (@AFCAjax) 24 September 2017
#DavyBedankt pic.twitter.com/v8W0afbdVr
— AFC Ajax (@AFCAjax) 24 September 2017