Both fell behind. Both fought back. Both won. United beat Aston Villa away, 3-2, on Saturday. City beat visiting Tottenham, 2-1, on Sunday. At the end of the weekend, the Manchester clubs occupied the top two places, as they have for most of the last year.
The similarities don't end there. Javier Hernández came off the bench to score two of United's goals. He also claimed the third, which was deflected in by Ron Vlaar. Hernández hasn't started a league game since late September but three times in two weeks he has come on and scored as United has fought back to win.
Edin Dzeko came off the bench to score the winner for City with three minutes left. Six of his seven goals this season have come as a substitute.
United keep coming from behind to win. This was the eighth time this season it has done so. City keeps scoring late to win. It won the title in added time last season. On Tottenham's last visit, in January, it won with a penalty at the end of a period of added time that was pivotal in both clubs' season.
There are reasons both Manchester teams are so dangerous at the end of games. Part of it is self-belief or sheer force of habit. Part of it is the style they play and their strength in depth. They wear opponents down.
United held the ball 70 percent of the time against Villa. City had more than 60 percent of the game's possessions against Spurs.
In addition to Chicharito, United was also able to call Tom Cleverley and Anderson off the bench. The midfield tempo never slowed. In the end Villa began to make small mistakes, like the slight raggedness in its defensive line that kept Hernández on side for the crucial first goal. He stole the headlines, but the hero could equally have been Robin van Persie, who hit the bar twice in a minute.
City was able to bring on Maicon to pin down Tottenham's left flank. That's where the first goal came from. Dzeko's well-taken winner came when he reacted faster than Michael Dawson, who had only just come on to replace the weary Kyle Walker as Spurs reshuffled its defense.
Yet the apparent similarities in the results of the two Manchester teams disguises the differences in the way they get there.
Mancini is developing a reputation as a tactical tinkerer who can't make up his mind. In truth, Mancini is consistent. His first, very Italian, objective, is to take control of the game and stifle the opposing attack. He doesn't want to lose. It's no coincidence that City is the only unbeaten team in the Premier League.
The City squad is built to bully opponents. On Sunday it committed 16 fouls against Tottenham, most of them in a fractious first half as it battled to dominate the midfield. The fact that it conceded a goal, against the run of play, hardly mattered.
When City had established control, Mancini was ready to go on and win the game. He switched to a back three and brought on Maicon. If Sergio Agüero and Carlos Tévez had been a little more accurate and Brad Friedel a little less inspired, the game would have been decided long before the end. But Mancini still had Dzeko up his sleeve to win a game in which City had long been in control.
On Saturday, United defended like toilets for the first 50 minutes. Both Villa goals developed down the United right where Rafael, notionally the right back, was absent both times. For the first, on a Villa counter-attack, Chris Smalling, who is 6-foot-4, was simply bullied backward by Christian Benteke. But to single out Rafael and Smalling is a little unfair. Every time Villa attacked in the first half, the United defense evaporated. If the home team's decision making, particularly from wide positions, had been a little better, it could have led by four or five.
That all changed as United scored three, taking its league tally to 29 in 11 games. You score two; we will score three. What was noticeable was not just that the United attack had found its familiar edge, but that its defense had suddenly rediscovered its focus, its steel and its determination.
"When they need to do it, they do it," Ferguson said of his players. But it is also a worrying trait. Why can't this adrenaline junkie of a team "do it" from the start?
Of course, a dearth of strikers is a less pressing problem when players in other positions are scoring. Early on it seemed as if the afternoon, like the whole season at Stamford Bridge, would be dominated, by John Terry.
Curiously, the Chelsea captain returned from suspension on Remembrance Sunday to find that the Royal Chelsea Hospital, Britain's showcase home for military veterans, had found a black Chelsea Pensioner to shake his hand.
Terry grasped the initiative for his team with a typical header from a corner. It was his 50th Chelsea goal -- a huge number for a center back. But then things took a nasty twist. For once, Luis Suárez fell when he didn't mean to, shoved from behind by Ramires. Suárez crashed into the unprepared Terry, who collapsed. Terry was carried off on a stretcher, which is one bad sign. The problem seemed to be with his knee, which is another bad sign. Chelsea, which had shown so much fighting spirit during the games when its combative leader was suspended, deflated. When Suárez levelled for Liverpool in the second half that was pretty much it.
Earlier, Fellaini broke the Sunderland defense and created both goals as Everton came back to win 2-1 at home. Fellaini has plenty of skill, as the backheel that set up the winning goal showed, but that technique comes in a 6-foot-4 body which he uses to batter defenders. He is one of the chief reasons Everton is in fourth place.
Dembélé's worth has only been emphasised by Tottenham's midfield struggles in his absence. When fit, he has the skill and speed to run round opponents and the power to run right over them.
These aren't the only brawny Belgians in the Premier League. Vincent Kompany is a tank. Thomas Vermaelen and Jan Vertonghen are smooth defenders with hard edges. At 5-foot-7, Eden Hazard is a rare small Belgian in the Premier League.
The days when everyone stepped on Belgium seem to be over.