Alli found the net twice as Spurs ran out 3-1 winners at Wembley to secure their place in the last 16 of the Champions League, but speaking after the game he was left ruing a late chance to score a sensational hat-trick.
In his first European game of the season following suspension, Alli was presented with a great chance to score a treble, only for him to fluff his lines when presented with a free header following Kieran Trippier's cross from the right.
Speaking to Norweigian TV channle 'Viasport' after the game, the 21-year-old admitted his frustration, but insisted that the win was the most important thing, saying: 'I'm disappointed I didn't get the hat-trick to be honest. I had an easy chance at the end from a great ball in by Kieran.
'More importantly the team got the win today. I'm delighted to get the two goals, I was looking forward to getting back into the Champions League after my ban, it's a great result'.
Meanwhile, the England man was shocked by how much space Spurs were awarded by their illustrious neighbours.
'We spoke about it after the first game, we couldn't believe the space we had at times at their place. We don't want to just compete with these teams we want to beat them,' he said.
Christian Eriksen, who scored the other goal for the hosts concurred, telling 'BT Sport': 'We had chances to score more if we had the composure. We need to keep it going, we had to make it up from last week.'