Brown Ferguson urged caution after seeing Stenhousemuir take a big step into League One.
Mick Dunlop's double gave the Warriors the advantage in the promotion play-off final, but Ochilview chief Ferguson warned "it's only half-time," in the tie.
The sides meet again on Saturday at Balmoor to decide who replaces Queen's park in the third tier of Scottish football.
Jim McInally wasn't optimistic of his side's chances - even at home. The Blue Toon boss lamented his injury list and striker Rory McAllister missing "his first penalty in about five years".
MATCH REPORT: Stenhousemuir 2 Peterhead 0.
Stenhousemuir are hoping for a bumper travelling support. Keep up to date with the plans at the Warriors' website.