His precision finish after 74 minutes - a ninth goal of the season for the midfielder - moved the Magpies two points ahead of West Bromwich Albion at the summit.
Preston goalkeeper Andrew Lonergan saved a Jonas Gutierrez cross after 12 minutes and a Nolan straightforward shot from outside the box two minutes later.
Alan Smith elbowed Chris Sedgwick and was booked after 16 minutes.
From the resulting free-kick, Preston striker Neil Mellor beat two defenders when he was played through on goal down the right wing and Newcastle goalkeeper Steve Harper parried his powerful driven shot.
Mellor found Preston striker Chris Brown just inside the penalty area and he turned and had a tame 12-yard left-foot shot saved after 37 minutes.
Paul Parry found Mellor and his shot was straight at Harper after 44 minutes.
Preston replaced injured centre-back Youl Mawene with Liam Chilvers at half-time.
Lonergan saved a cross from Jose Enrique after 48 minutes.
Michael Tonge, who was making his debut on loan from Stoke City, took an indirect free-kick to Parry and his 30-yard left-foot drive was saved after 53 minutes.
Danny Guthrie's out-swinging corner was saved two minutes later and Brown's cross was saved after 58 minutes.
Nile Ranger replaced former Preston former loan player Andy Carroll after 62 minutes.
Sedgwick's cross was saved after 63 minutes and Tamas Kadar replaced Danny Simpson two minutes later.
Eddie Nolan replaced Preston captain Callum Davidson after 73 minutes.
Guthrie crossed to Kevin Nolan on the left and he scored from inside the area into the bottom right corner after 74 minutes.
Mellor found Eddie Nolan and he had a shot saved after 79 minutes and Jon Parkin replaced Sedgwick a minute later.
Lonergan saved a Ranger shot and Parry had a cross saved after 83 minutes.
Peter Lovenkrands replaced Guthrie after 90 minutes and Mellor had a shot saved in stoppage time.