Shearer, the man for all occasions, continued his liking for Leeds with a stunning early winner, timed at 3 mins 20 secs.
With The Magpies having arguably their best first-half showing of the season at home, Shearer pounced with a stunning strike for his third goal of the season against The Whites- he got both goals on the opening day of the season in the 2-2 draw at Elland Road.
And the win hoisted United up to sixth place from eight as they overtook both Southampton and their next home opponents Fulham.
Yet the way Toon started it looked as if they would be on course for a goals avalanche as they railroaded the Leeds defence.
It could not have started better. A clever lay-off by Kieron Dyer into the path of Nobby Solano saw the Peruvian charge at the Leeds defence.
Solano played in Shearer who didn't have to break stride and from the right of the area drove across Paul Robinson. It was the 33-year-old's 16th goal in 18 league appearances this season.
From then on in the opening half it was a one-way procession towards the Leeds goal as Newcastle squandered numerous chances.
Kieron Dyer shot wide, Paul Robinson saved superbly from Jermaine Jenas, and just after the half-hour the referee, Phil Dowd, astonishingly waved for play to continue after Robinson tripped Dyer just outside the Leeds penalty area.
Newcastle old boy David Batty was given a generous round of applause from the home fans when his injury jinx struck again and he was forced off on the half-hour and replaced by Salomon Olembe.
Jermaine Jenas was denied his first goal of the season by the fingertips of Robinson before Dyer broke clear and shot wide, claiming he was fouled by Robinson in the process.
Three minutes from the break Shearer found himself on the penalty spot only to direct his effort wide as did Dyer in time added on when once again he was in the clear.
Solano then volleyed an Olivier Bernard cross wide before Leeds managed their first shot on target after 59 minutes when Shay Given held on to a Viduka header at the second attempt.
Leeds failed to register a shot on target in a woeful first-half performance but came into more in the second-half as the impressive Mark Viduka nutmegged Titus Bramble to tee up Dominic Matteo, who responded with a poor finish.
Michael Bridges then miskicked after creating a clear opportunity for himself, as he turned inside Bramble but failed to connect with his shot.
Newcastle would have kicked themself had they lost this match as Gary Speed came close to scoring against his former side when heading a Laurent Robert corner against the near post in the 61st minute.
After Bridges had given Newcastle another scare, Hugo Viana - a replacement for Robert ten minutes from time - forced a full-length fingertip save from Robinson.