The Manchester United striker scores a treble for second game running in 5-0 win over Bolton, to keep his side top of the table on goal difference from Manchester City.
'It could have been more' claims hat-trick hero Wayne Rooney
On the last game day, both clubs recorded mammoth victories - 5-1 and 8-2 over Tottenham Hotspur and Arsenal, respectively - and yesterday was more of the same.
Javier Hernandez scored twice on his first start of the season.
Rooney told ESPN: "We always know Bolton is a difficult place to come. We got an early goal and kicked on from there. First start with Chicharito [this season] and both scoring, that's great."
Hernandez missed several chances to complete a hat-trick of his own, but said: "The most important thing here is the result."
On his partnership with Rooney, he added: "Every player can play with Wayne Rooney. He's a world-class player. He can do anything."
The victory ensured United did not allow City to steal a march on them with their earlier triumph.
Sir Alex Ferguson, the United manager, said: "You just have to concentrate on yourselves. It's a difficult start to the season, we've got all the bigger names. We've got Chelsea next Sunday.
"It's a hectic start and if we come through it, we'll have done well."
It is United's best start to a Premier League season and Rooney took his personal tally to eight in four games, part of an overall team tally of 18, 13 of which have come in the last two matches.
Indeed, aside from City, Rooney has now scored more league goals on his own this season than any of the clubs attempting to keep pace with this astonishing start.
Indeed, the only downside for Ferguson ahead of another Champions League quest getting under way against Benfica on Wednesday was the suspected broken foot that the midfielder Tom Cleverley sustained in a collision with Kevin Davies, and an injury to Jonny Evans.
The goals flowed from the off. Four minutes in, Nani danced down the right wing and when he flashed over a low cross, Hernandez left Gary Cahill standing with some exemplary movement before nicking the ball home at the near post.
Rooney then netted a carbon copy of his strike partner's early effort and minutes later, Phil Jones, playing at right-back, began a gallop on halfway that took him weaving into the Bolton area.
Jussi Jaaskelainen blocked Jones's shot straight to Rooney, who stroked into the far corner.
In the second half, Michael Carrick's shot was deflected into Hernandez's path, and the Mexican wasted no time in belting home.
Another Nani cut-back then set up Rooney to complete his second successive hat-trick, following Les Ferdinand, Ian Wright and Didier Drogba in achieving that particular feat during the Premier League era.
And with both Manchester clubs having yet to drop a point, it has already turned into a fascinating duel.