Ballack set Chelsea on course for their first win at Newcastle since 2001
Goals from Michael Ballack and Florent Malouda handed Chelsea a deserved win against Newcastle and ensured the title race will go down to the final day.
Michael Owen had two first-half chances to give Newcastle the lead, while Ballack miscued when through on goal.
But Chelsea took control after the break, Ballack nodding in on 61 minutes and Malouda calmly adding a second.
The win moved Chelsea level on points with Manchester United, though their goal difference is vastly inferior.
Grant's half-time talk had the desired effect
United, travel to Wigan on Sunday knowing a victory will see them retain their Premier League crown bar a freak scoreline for Chelsea, while the Blues play Bolton at Stamford Bridge.
Blues boss Avram Grant will be buoyed by Wigan's recent run of results - they are unbeaten in five - and the current form of his own team, who have not lost in the league since 16 December.
Chelsea arrived at St James' Park fully aware that defeat would effectively end their title hopes but it took them more than half an hour to establish any sort of rhythm and Newcastle will rue their failure to take their chances during that period.
Inside five minutes Owen latched onto Nicky Butt's lobbed through-ball but volleyed high over Petr Cech's cross-bar and moments later Habib Beye slithered past Wayne Bridge and into the Chelsea penalty area, only to produce a wayward cross from a dangerous position.
The hosts' big opportunity arrived in the 28th minute when Obafemi Martins worked his way into the box and, after the on-rushing Cech foiled Mark Viduka, Owen's follow-up was cleared off the line by a perfectly positioned John Terry.
Grant selected Nicolas Anelka and Malouda to support Drogba in attack and the potential threat posed by the pacy trio forced Newcastle's back four to sit deep.
That enabled Chelsea to advance in numbers and when Michael Essien broke from midfield and slipped Ballack through on goal there should only have been one outcome.
But Ballack's first touch was poor, taking him away from goal on the left, and his subsequent shot was even worse, slicing the ball wide of Steve Harper's right-hand post.
Keegan was pessimistic on his side's chances of catching the top four next year
Crucially, though, Chelsea had built up momentum and managed to carry it into the second half, the early stages of which they comprehensively dominated.
In the 52nd minute Drogba flicked Mikel's pass into the path of Ballack and only Steven Taylor's last-ditch challenge prevented the German a clear sight of goal.
From Malouda's resultant corner, Terry thumped a header against Harper's bar but the hosts' reprieve would only be temporary.
On the hour mark Abdoulaye Faye committed a reckless foul to prevent Malouda driving into the box and Ballack rose completely unmarked to head home Drogba's free-kick from the right.
Given their superiority, Chelsea would have wanted to push for a second immediately but instead found themselves on the back foot.
Martins saw a fierce drive deflected narrowly wide and then Butt's miscued shot was met by Owen, whose connection was insufficient to divert the ball past Cech.
Punishment almost came in the form of a blistering Ballack drive that stung Harper's palms, but then it did when a neat exchange of passes between Ballack and Essien allowed Lampard to release Malouda for a precise finish that kept Chelsea's title hopes alive.
Newcastle manager Kevin Keegan:
"I like Avram Grant very much and think this Chelsea side is exceptional.
"In any other season they would have been worthy champions but I can't see Manchester United slipping up at Wigan - even on that pitch, which isn't very good.
"I think we gave Chelsea a hell of a game in the first half today but their class shone through.
"But they are both quality sides with great players, who will be worthy champions." More Keegan quotes
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