Hungary remain the underdogs to qualify for Euro 2016 despite their first-leg play-off win, according to coach Bernd Storck.
The Hungarians have one foot on the plane to next year's tournament in France after debutant Laszlo Kleinheisler earned the visitors a 1-0 victory over Norway in Oslo on Thursday.
Kleinheisler, 21, scored the only goal of the match midway through the first half as Hungary drew first blood.
Storck, however, said via UEFA.com: "Norway remain favourites - they have excellent players.
"We need to play like we did today, or we will have problems [in Budapest on Sunday].
"We are in a good position [leading 1-0 after the first leg]. We did this for Hungarian football. We want to complete this job on Sunday - we need success."
Norway were unfortunate to be trailing Hungary after an end-to-end first half.
The home team did dominate possession in the second but lacked cutting edge up front - Pal Helland almost rescuing a draw for Norway in the closing stages, only to see his effort hit the crossbar.
Norway boss Per-Mathias Hogmo remains upbeat about his team's chances heading into the return leg, though.
"We are at the halfway stage [of the tie]. We are already looking forward to the return in Hungary," said Hogmo.
"We played well, made a fantastic start and created two early chances. Unfortunately, we were not sharp in the box.
"I told the players: let this result motivate you for Sunday."