FROM cautious hope to abject despair inside a couple of hours.

As if their own defeat - which ended any chance of Champions League progress - was not tough enough for Celtic to take, this surprise scoreline in Amsterdam compounded the suffering. It confirmed that Neil Lennon's side will not have any continental competition to look forward to in the new year.

Ajax, though, now travel to Milan on matchday six knowing that a win would propel them into the last 16 after beating Barcelona. Thulani Serero and Danny Hoesen scored to give the Dutch a half-time lead and, despite defender Joel Veltman being sent off after a challenge on Neymar and Xavi pulling a goal back from the penalty spot, Frank de Boer's side held on to earn a huge victory.

Serero ghosted in late for the first goal in the 19th minute, applying the touch to a cross from the right from full-back Ricardo van Rhijn, who just five minutes earlier had made a goal-saving tackle on Neymar.

The South African's first Champions League goal precipitated a period of sustained pressure from the young Dutch side, culminating in a second goal three minutes from the break. A poor clearance by Javier Mascherano allowed Viktor Fischer in and, although his shot was parried by goalkeeper Jose Manuel Pinto, Hoesen picked up the rebound, rounded Carles Puyol and score with the help of a deflection off Gerard Pique.

The comfortable cushion deflated just two minutes after the break, though, when Van Rhijn's poor back pass set Neymar away and Veltman tripped him on the edge of the area, conceding a penalty and getting himself sent off. Xavi converted the spot kick but Ajax held on to condemn Barcelona to a first defeat under new coach Gerardo Martino and end hopes of a record-equalling longest unbeaten start to a season.