Two goals by Frenchman Yohan Cabaye and one from Papiss Cisse gave Newcastle a sixth straight victory to put them three points above Tottenham Hotspur and three behind third-placed Arsenal with a game in hand.
Chelsea, who dug in for a point at Arsenal despite making eight changes from the side that beat Barcelona in midweek, are now four points behind Newcastle with four games left and struggling to qualify for next season's Champions League.
Tottenham's dismal run, which has brought only one win in nine league games, continued as former player Adel Taarabt scored QPR's winner with a free-kick before half-time to lift them three points clear of the relegation zone.
Taarabt was later shown a red card but QPR held on.
Blackburn Rovers gave themselves fresh hope of avoiding the drop with a 2-0 home defeat of Norwich City, although they stay in the bottom three, while fellow strugglers Bolton Wanderers drew 1-1 at home to Swansea City.
Wigan Athletic came down to earth after back-to-back wins against Manchester United and Arsenal by losing 2-1 at Fulham, while Aston Villa are still looking over their shoulder after drawing 0-0 at home to Sunderland.
Sandwiched between the first and second legs of Chelsea's Champions League semi-final against Barcelona, the lunchtime London derby at Emirates Stadium proved unappetising with a draw not much use to either club in the light of Newcastle's victory.
Newcastle took full advantage of the stalemate with Cabaye heading them in front from close range before Cisse, whose goals have fired Newcastle upwards, combined with the Frenchman to make it 2-0. Cabaye curled in Newcastle's third after the break.
In the battle to finish in the top four, Arsenal have 65 points from 35 matches, Newcastle have 62 from 34 while Tottenham have 59 from 34. Chelsea, who will try to defend a 1-0 lead in the Nou Camp on Tuesday, are sixth with 58 from 34.
"It's been a great season," said Newcastle manager Alan Pardew. "We targeted the last 10 games and said if we could be in and around it. Now we've just got four left and we'll try and win every one of them."
DROGBA MISSING
Robert Di Matteo's Chelsea, playing their third game in six days, reshuffled their side with Didier Drogba, scorer against Barca, not included because of a knee injury.
They were resolute at the back, with John Terry and Gary Cahill, who repelled everything Barca could throw at them in midweek, again impressive, restricting Arsenal to few chances, the best of which was a Laurent Koscielny header that smacked the crossbar in the opening period.
"It was a brilliant team performance," Di Matteo told Sky Sports. "The organisation, team spirit, effort and commitment was great. It was a magnificent point.
"This was our third game in six days, which personally I feel is crazy but we showed there is a great quality in this team."
