Ajax had to rely on sought-after midfielder Christian Eriksen to grab a 3-3 draw at Heerenveen after the champions blew a two-goal lead.
Eriksen struck in the 65th minute after the Amsterdammers had threatened to throw away all the points.
Goals from Niklas Moisander (13) and Kolbeinn Sigthorsson (17) suggested an easy night was on the cards but by half-time the game had turned completely.
Alfred Finnbogason levelled matters with a quickfire double before Magnus Wolff Eikrem sent Heerenveen ahead a minute before the break.
Ajax lost 3-2 on the opening day at AZ Alkmaar and Eriksen at least ensured there was no repeat as he netted his second of the season.