OSLO, Sept 26 (Reuters) - Frode Johnsen hit a hat-trick as Rosenborg Trondheim routed Helsingborg 6-1 in a Champions League Group F match on Tuesday.

Johnsen scored the opening two goals in the 20th and 29th minutes, the second a header from a corner, and completed his hat-trick with his side's sixth in the 78th minute.

Roar Strand dashed any hopes the Swedish side had of salvaging the game by striking twice within two minutes early in the second half. Rosenborg's other strike came from a Stig Johansen own goal in the 64th minute.