Chelsea's chances of reclaiming the Premier League title were given a huge shot in the arm on Sunday as a 1-0 win over Manchester United sent Carlo Ancelotti's side five points clear at the top.
Chelsea captain John Terry was credited with applying the decisive blow with a header from Frank Lampard's 76th-minute free-kick, although Nicolas Anelka also celebrated as if he had got the final touch.
Either way, Chelsea were undeniably fortunate to take all three points after a contest that a depleted United side had controlled for long periods.
With a virtually full strength squad to pick from, Ancelotti resolved his one selection issue by opting for Deco rather than Joe Cole at the sharp end of his midfield diamond.
Sir Alex Ferguson, in contrast, had his options limited by the absence of the injured Dimitar Berbatov, although the United manager may well have, in any case, opted to start with Wayne Rooney as a lone striker ahead of a five-man midfield.
With a lingering calf strain restricting Nemanja Vidic to a place on the bench and Rio Ferdinand looking increasingly like a long-term absentee, Wes Brown and Jonny Evans assumed responsibility for keeping tabs on Anelka and Didier Drogba.
It was a task United's back-up centrebacks managed with some accomplishment in an evenly-balanced opening period that was easy on the eye yet devoid of clear cut scoring chances from either side.
On the one first-half occasion in which Drogba got a sight of goal, the Ivory Coast striker directed his header, from Branislav Ivanovic's cross, wide of Edwin van der Sar's left-hand post.
Anelka appeared more of a threat, particularly when dropping deep or wide to give himself the space to run at United's defenders.
The Frenchman had already tested van der Sar with one, skidding long range effort when, just after half an hour, he cut inside Patrice Evra from the right and curled a left-foot shot towards the far corner.
Van der Sar, diving full length to his right, proved equal to the challenge.
Petr Cech was not tested in similar fashion but United were not without opportunities of their own.
The visitors appeared to have legitimate claims for a penalty with quarter of an hour gone when John Terry muscled Antonio Valencia to the ground as the United winger threatened to go past him in the box.
And Ryan Giggs will have been frustrated not to have made more of the Darren Fletcher through ball which found him unmarked on the edge of the Chelsea box.
United's captain would have had the time to bring the ball down but opted to try and chip Cech with a first-time volley that comfortably cleared the cross bar.
Deco's ineffectual involvement in the match ended in the Portugal playmaker making way for Cole with just under half an hour left.
By that stage, United were looking the more likely winners with Rooney increasingly troubling the home side's back four.
A neat combination with Valencia on the right enabled the England forward to send a low drive inches wide, minute before he unleashed a curling shot that Cech clawed to safety as it dipped towards the top corner.
It was Chelsea however who were to have the final word after the outstanding Darren Fletcher was adjudged, debatably, to have fouled Ashley Cole close to the left touchline.
A United defence that had been scarcely troubled all afternoon made a hash of defending Lampard's inswinging delivery and Terry was unmarked as he rose to glance the ball past van der Sar.