The Blues ran out comfortable 2-0 winners thanks to second-half goals from Frank Lampard and Florent Malouda, with the result keeping alive their Premier League title challenge.
Guus Hiddink's side are just a point behind leaders Manchester United, though Sir Alex Ferguson's men, who face Aston Villa at home tomorrow, have two games in hand.
The game, however, was not without controversy, with United captain Michael Owen having what TV replays showed to be a perfectly good goal ruled out late in the game.
Meanwhile, the result leaves sorry Newcastle three points adrift in the relegation zone and facing a do-or-die visit to fellow strugglers Stoke City next Saturday.
Shearer had suffered a blow on the eve of the game when defensive duo Steven Taylor and Sebastien Bassong, both injured against United's previous game against Arsenal, failed fitness tests.
He was forced to switch right-back Habib Beye to centre-half in their absence, while Nicolas Anelka led the line for Chelsea after recovering from his recent toe injury.
Both sides found it hard to create clear-cut chances in a keenly-contested first half, though Steve Harper did well to deny Salomon Kalou in the 19th minute.
And a minute later Obafemi Martins should have done better when Jose Enrique sent in a low cross from the left, with the striker shooting wide of Petr Cech's goal.
Shearer also lost Peter Lovenkrands to injury shortly before the break, and he sent on Damien Duff, who missed the Republic of Ireland's two internationals with a hamstring problem.
Martins had another chance nine minutes into the second half when he got in front of John Terry, but his right-footed shot was hopelessly over Cech's goal.
And United were quickly made to pay for that miss when Fabricio Coloccini failed with a clearance, setting up a chain of events that would see Lampard head into an empty net.
Newcastle's fans then attempted to lift the spirits of Shearer's players, who then found themselves 2-0 down in the 65th minute and seemingly dead and buried.
Anelka flicked on a long ball for Lampard, who played Malouda in and the midfielder coolly beat Harper to leave United even deeper in relegation trouble.
Shearer then withdrew the ineffective Kevin Nolan and replaced him with fit-again Danny Guthrie, who had been out of action since mid-January with a hamstring problem.
There was controversy in the 73rd minute when a deflected shot from Owen was adjudged not to have crossed the line by Rob Styles' assistant before it was cleared by Ashley Cole.
Television replays showed the goal should have stood and Owen himself could be seen gesturing that he believed it had been at least a foot over the line.
And there was no way back for Shearer's side, who will go to the Britannia Stadium knowing anything other than a win will see them staring relegation in the face.