Chelsea failed to close the gap on Premiership leaders Manchester United after a goalless draw at Newcastle.
It was a frustrating afternoon for Chelsea boss Mourinho
The Blues would have been just one point behind the Reds had they won at Newcastle but never really found their form and created few openings.
Frank Lampard shot over, Salomon Kalou had a tame stab at goal and Joe Cole missed by inches in injury time.
Chelsea keeper Petr Cech made a good save from Kieron Dyer, while Obafemi Martins headed over from a corner.
But in truth it was a poor game - and an especially disappointing performance from Chelsea given the opportunity that was before them.
Jose Mourinho's team rarely looked like taking advantage of United's draw at home to Middlesbrough on Saturday.
The weekend's results mean Chelsea are three points behind United, who they play on 9 May, but with a vastly inferior goal difference.
There were no clear-cut openings in the first 45 minutes, though Newcastle played with the greater sense of urgency and did create several half chances.
Kieron Dyer hooked the ball wide under pressure, while a deflected Martins strike missed the target and a promising position for Stephen Carr came to nothing after he cut in from the left.
Chelsea went in to the match with Michael Ballack and Claude Makelele restored to the starting line-up.
But German Ballack limped off after 18 minutes following a heavy challenge from Titus Bramble.
The Blues did have one opening in the first-half, but John Terry headed wide from a Frank Lampard free-kick under pressure from Antoine Sibierski.
Terry cut a frustrated figure as he appealed for a penalty, claming that Sibierski had impeded his run.
Chelsea played with more endeavour and purpose after the break - and soon created an opening, though Lampard drilled the ball over from 10 yards.
Newcastle underlined their attacking threat with two chances in a minute.
Cech smothered Dyer's shot after Nicky Butt had played him in, and from the resultant corner Martins, unmarked, headed over.
Chelsea responded, with Butt clearing up after Kalou guided the ball goalwards following a low drilled cross from substitute Joe Cole.
Mourinho introduced Andrei Shevchenko with 15 minutes remaining and the visiting team - with a great record of scoring late on - pushed forward in search of a decisive goal.
Terry's entanglement with Sibierski continued - and the Chelsea skipper's rant at referee Mark Halsey hinted at his growing frustration.
Cole deflected a Paulo Ferreira cross narrowly wide in the third minute of stoppage time as Newcastle held on to claim a point and dent Chelsea's title aspirations.
Newcastle boss Glenn Roeder:
"I'm very proud and pleased for them. They have taken a bit of flak recently but they have put on a real performance against the champions.
"I think we played some very good football at times.
"I think that over the full 90 minute a draw was the fair result. I do not think that there was a bad performance from any of my players."
Chelsea boss Jose Mourinho:
"It was a chance missed to close the gap - but at the same time we had an away game and Man United had a home game and at the end of it the gap between us is the same."
Newcastle: Harper, Solano, Bramble, Taylor, Carr, Milner, Butt, Dyer, Emre, Sibierski (Carroll 78), Martins.
Subs Not Used: Srnicek, N'Zogbia, Ramage, Babayaro.
Chelsea: Cech, Ferreira, Essien, Terry, Bridge, Wright-Phillips (Joe Cole 55), Makelele (Shevchenko 76), Lampard, Ballack (Mikel 18), Drogba, Kalou.
Subs Not Used: Cudicini, Boulahrouz.
Booked: Essien, Mikel, Lampard.
Ref: M Halsey (Lancashire).