League Two pacesetters Wycombe overcome Barnet, who finish the FA Cup first-round tie at The Hive with nine men.
John Akinde rounded keeper Matt Ingram to put the Conference leaders ahead.
Ingram made a series of saves before Paul Hayes levelled from the spot after Andy Yiadom fouled Matt McClure.
Sam Togwell was shown a red card for a tackle on Matt Bloomfield, and Aaron Pierre's header and a Sam Wood tap-in sealed victory for Wycombe before Yiadom was also sent off.
Yiadom, who escaped punishment after conceding the first-half penalty, was shown Barnet's second straight red card for his challenge on Josh Scowan.