McManus won it for the Owls (2-0) after Kee-ayre Griffin intercepted Ryan Radcliffe's pass to end Central Michigan's lone overtime possession.
Central Michigan (1-1) forced overtime with David Harman's 31-yard field goal with 1:11 left in regulation. The Chippewas, winners of three of the last four conference titles, had won 18 straight against MAC East Division teams.
Central Michigan had a chance to win in regulation after Temple fumbled on its own 35 with 35 seconds to go. Radcliffe completed a 3-yard pass to Paris Cotton, but the quarterback then wasted considerable time - electing not to spike the ball to stop the clock - and fumbled way behind the line of scrimmage in the final seconds.
A week after making a late field goal to beat Villanova, McManus missed two first-half attempts before giving the Owls a 10-7 lead in the third quarter with a 31-yarder.
Temple's Bernard Pierce opened the scoring with a 4-yard run late in the first half, and Central Michigan tied it in the third quarter on Cotton's 1-yard run.
Temple is 2-0 for the first time since 1981.