Chelsea midfielder Frank Lampard admits the manner of their win at Champions League opponents Nordsjaelland wasn't top class.

The 34-year-old admitted the way Chelsea became "lax" on Tuesday night after Juan Mata put them ahead was a concern.

"A little bit, but I think it is always hard to dominate a Champions League game away from home from start to finish," he said.

"We played Genk last year and drew 1-1, a team not so fancied in the big picture but they can be tough games.

"I don't think they will give Juventus and Shakhtar easy games either."