The Foxes were a depleted team from the half hour mark when Richie Wellens was sent off for a second yellow card.
The midfielder was booked on 17 minutes for a foul on Alan Smith and again on 30 minutes when he held back Wayne Routledge.
The draw enabled Newcastle to match a club record of 14 league matches unbeaten. It was the first time the Magpies had achieved that unbeaten run since 1950.
The first chance fell to Newcastle when Kevin Nolan hit an angled drive into the side-netting.
City created an opening on 15 minutes when Paul Gallagher found Matt Fryatt inside the penalty area but the City striker was muscled off the ball by defender Mike Williamson.
Midway through the first half Steve Harper conjured up a finger-tip save to keep out Fryatt's 12-yard drive before Wellens was shown his red card.
Fryatt then turned Williamson on halfway and evaded four challenges on a mazy run into the penalty area where he was unfortunate to see his goalbound strike blocked by Patrick van Aanholt.
Newcastle responded with a swift break which saw Chris Weale claw away van Aanholt's carefully placed drive.
Leicester were on the offensive from the restart with a Gallagher free-kick ricocheting off the defensive wall for a corner.
United threatened soon after when Nolan headed van Aanholt's cross just over before Martyn Waghorn dragged a shot just wide for Leicester.
Andy King then tested Harper with a near-post header from a Waghorn corner with City claiming a handball by Nicky Butt.
Newcastle began to push forward as depleted Leicester tired with substitute Nile Ranger having a headed goal ruled offside and Butt crashing a drive just wide but City held their ground for a deserved point.