The keeper's impressive save from the spot-kick ensured Millwall held on to the point that their battling display deserved.
Matt Heath's second goal in two starts set City on their way after on 46 seconds, the centre-back rising to head home Izzet's chipped free-kick.
And when Jordan Stewart drilled a shot under Warner a mere two minutes later the writing was on the wall for Mark McGhee's men, but they were dealt a helping hand as Brian Deane was dismissed for a two-footed lunge on Wise, having already been booked 60 seconds earlier.
To his credit former Leicester boss McGhee changed tactics soon after as Steven Reid came on for his first football since the World Cup and reduced the arrears within three minutes, as he sidefooted home after Ian Walker could only parry Andy Roberts' volley.
And the Republic of Ireland international nearly added a second as his fierce drive forced Walker to tip over. It was impossible for the game to continue at its break-neck speed and predictably the pace slackened.
Izzet's looping header came back of the crossbar just before the break, but after the restart it was one-way traffic as the Lions besieged the City goal.
But Wise levelled things sidefooting home from close in and former city striker Claridge then spurned a chance to put Millwall ahead, but Leicester were gifted a last-gasp opportunity to steal the points.
Matt Lawrence hauled down Frank Sinclair in the area. Warner proved himself to be the hero of the day, but only with a little help from Wise.