The United skipper expertly put away a second-half header to go top of the Premiership charts with what proved to be an unlucky 13th goal of the season as far as Spurs were concerned.
Both sides went into the match knowing that whoever claimed maximum points was guaranteed fourth position and an eighth successive home win ensured it was Newcastle who took the honours.
Spurs will argue that they deserved at least a share of the spoils while on the other hand Newcastle wasted chances galore.
Gary Speed drove Newcastle infront after 17 minutes when he lost his marker Simon Davies to beat Kasey Keller at his near post.
However six minutes later Speed left the field with a groin strain and looks certain to miss the New Years Day clash with Liverpool. Nobby Solano and Kieron Dyer, who were both substituted at half time with concussion and a calf strain respectively, are also doubtful for the visit of the Merseysiders.
Speed's goal came after Craig Bellamy had spurned a great chance when firing wide after latching on to a wayward Ledley King header. Spurs hit back and Mauricio Taricco's long-range effort was tipped over the bar by Shay Given.
Gustavo Poyet had a close-range volley beaten away by Given as he looked to add to his record of six goals in nine starts against Newcastle.
Newcastle doubled their tally on 58 minutes thanks to the persistence of Bellamy. A quick throw in by Laurent Robert was seized upon by the Welsh international who charged towards goal and, although his first chance was beaten down, he crossed perfectly at the second attempt for Shearer to head accross Keller and into the net.
Substitute Lomana Tresor Lua Lua should have increased the lead after 63 minutes when put clear by Shearer.
Bellamy kept in touch with Lua Lua who decided to go it alone and drove against an upright much to the annoyance of Bellamy.
Spurs were thrown a lifeline on 78 minutes when substitute Teddy Sheringham crossed from the right and Newcastle substitute Nikos Dabizas, throwing himself full length, only succeeded in heading into his own net.
Spurs piled on the pressure from then on but Newcastle defended in depth and managed to hang on for a crucial three points.