The difference was mistakes. Chelsea made significantly fewer around its own goal. It ruthlessly punished those that Tottenham committed. The first two goals came when Gary Cahill and then Juan Mata pounced on panicky clearances by William Gallas. Against his former club, Gallas suddenly showed his age and his nerves. He was also caught out of position for the third goal. Kyle Walker, desperately trying to play out of defense as time wound down, gave away the ball for the fourth.
Chelsea also showed its character. After strolling through the first half in total control, it was ambushed by two quick goals at the start of the second half. There was a brief period when Spurs looked capable of seizing the game, but Gylfi Sigurdsson kept shooting straight at Petr Cech. Chelsea gradually regained control.
After the game, André Villas Boas, who doesn't seem to have lost the habit of talking up Chelsea players, said the game was decided by "the individual brilliance and creativity that Chelsea has."
Oscar, Eden Hazard and Fernando Torres all showed flashes, but the difference-maker was once again Mata, who scored the two goals that turned the game with effortless aplomb.
Because of Mata, Chelsea came through a tough test of its title credentials with something to spare.
Yet Tottenham can clutch some straws of consolation in the misery of defeat. It played without its best all-round midfielder, Moussa Dembele, and its most dangerous attacking weapon, Gareth Bale. Dembele was injured playing for Belgium. Bale reportedly left the ground just before the game because his partner had gone into labor. It's a measure of how much attitudes have changed in a very short time, even in the macho world of professional soccer, that such a choice is nowadays considered automatic.
That left Clint Dempsey shoved out on the left wing in the first half, where he continued his early-season struggles at his new club.
Yet Spurs gradually played its way into the match. There was a brief spell in the second half when it looked capable of winning. In the ended it was still waiting and hoping. So, in a maternity ward, was Bale.
It's not that Rooney isn't good. He is. But he promised to be truly great. He isn't.
Friday marked the 10th anniversary of Rooney's first Premier League goal, a sensational, looping, long-range strike against Arsenal. Rooney had already become Everton's youngest ever scorer with a brace in a League Cup game.
At the age of 18, Rooney went to United for £25.6 million, a record for a player under 20. He immediately scored a hat trick in the Champions League.
Rooney looked capable of anything. He mesmerised defenders with his uncanny control and sense of what was going on around him. He dazed goalies with a series of pulverizing long-range Charltonesque strikes.
Yet while one of his early United teammates, Cristiano Ronaldo, has built on teenage precocity and developed into on of the two best players in the world, Rooney has not. Maybe the problem is mental. Perhaps Ronaldo has a single-minded desire and commitment that Rooney lacks. Perhaps the Portuguese cast a shadow from which Rooney cannot escape. Maybe the problem is physical. Unlike Ronaldo, the young Rooney was merely quicker than average. He seems to have lost what speed he had. Perhaps a series of injuries, notably the broken metatarsal in 2007, have robbed him of his athleticism. Maybe he is simply a more limited talent.
This doesn't mean Rooney is not still an extremely good player. Last season he scored 35 goals, his best total ever. But, in the United system a big central striker, which is not how Alex Ferguson has always used him, really should score. And he undoubtedly still carries the aura of a star.
On Saturday, as Manchester United entertained Stoke, Rooney provided an uncanny reminder of his ability to attract the spotlight. After 11 minutes, Rooney, defending at a corner, headed the ball into his own goal. Inspired, Stoke seized the initiative. Rooney deflated them, heading in Robin van Persie's wonderful cross. Both strikes were true center-forward finishes, as was his third of the afternoon, a simple tap in. He has an eye for goal.
United won 4-2 and Rooney had, once again made a decisive contribution. But watching him chug round the field did not conjure misty-eyed memories of the great Bobby Charlton, it instead evoked wistful recollections of another sensational United star of years gone by: the teenage Rooney.
By the way, the other 19 names on the England greats list were Lineker, Gascoigne, Beardsley, John Barnes, Colin Bell, Gerrard, Brooking, Clemence, Shilton, Ashley Cole, Trevor Francis, Gerry Francis, Hoddle, Keegan, Bryan Robson, Scholes, Des Walker, Madeley, Sol Campbell and, yes, Terry. Am I right?
On Saturday, away to in-form West Brom, City played almost 70 minutes a man short after James Milner was sent off. It fell behind to a goal by Shane Long. Yet when Edin Dzeko levelled with 10 minutes left, there was a sense of the inevitable. West Brom pressed. Joe Hart saved twice from Romelu Lukaku. Then, two minutes into added time. City broke away and Dzeko scored to secure a 2-1 victory.
One thing hasn't changed. City is winning.
This doesn't mean Norwich suddenly turned into thugs. One of the yellow cards, shown to Wes Hoolahan, was for the silly offense of putting the ball into the net after the whistle had blown. Another was for dissent by the argumentative Grant Holt. Lee Probert also seemed to be contemplating showing a fifth card to Steve Morison, for slapping the ball away, in the final minutes before being distracted by a Norwich substitution. But those two incidents showed that the Canaries had found some fight. Arsenal, meanwhile, utterly lacked any feistiness. The Norwich midfield surrounded Santi Cazorla every time he had the ball. He simply couldn't find a teammate. None of the other Arsenal players was able to summon a threat.
Norwich might well feel that four yellow cards for three points is a good rate of exchange.