Joey Barton gave Harry Redknapp's side the perfect start with a goal in the fourth minute before Charlie Austin's penalty 10 minutes before half-time doubled the advantage.
The Loftus Road outfit remain the only unbeaten side in the division with a three-point lead over second-placed Burnley, who won 3-0 at home to Charlton Athletic.
Danny Ings netted his 10th goal of the season in the 38th minute before strike partner Sam Vokes scored in the 67th and 86th minutes to seal a comfortable win for Sean Dyche's men.
Nottingham Forest had briefly gone second earlier in the day thanks to their 1-0 win over neighbours Derby County at the City Ground.
Jack Hobbs scored the only goal four minutes before half-time for Forest, with Derby's Richard Keogh being dismissed 12 minutes from time for a second bookable offence.
Leicester City remain in third, behind Burnley on goal difference following a 2-1 over Barnsley, who dropped to the foot of the table.
David Nugent opened the scoring five minutes into the second half before adding a second from the penalty spot 12 minutes later.
Jason Scotland pulled one back for Barnsley with 17 minutes remaining but they could not find an equaliser and fell to their seventh defeat in nine games.
Watford moved up to fourth in the table as substitute Cristian Battocchio's goal eight minutes from time gave them a 1-0 win over visiting Wigan Athletic, while Reading moved into the top six after defeating Birmingham City 2-0 at home.
Danny Guthrie scored both goals, in the 32nd and 75th minutes, as Birmingham fell to their third defeat in four games.
David McGoldrick scored two goals in quick succession midway through the first half to hand Ipswich Town a 2-0 home win over Brighton and Hove Albion, while Blackburn Rovers moved into the top half with a 3-1 win away at Bournemouth.
Jordan Rhodes opened the scoring in the 10th minute, before Leon Best made it two 14 minutes later.
Rhodes then bagged his second from the penalty spot four minutes before the break, and things went from bad to worse for Bournemouth as Richard Hughes was dismissed for a second booking seven minutes after the interval.
Ryan Fraser did come off the bench to pull a goal back for the hosts in the 74th minute but Blackburn held on to their advantage to move up to 11th.
At the wrong end of the table, winless Sheffield Wednesday's troubles continued as Federico Macheda's goal in the 71st minute condemned them to a 1-0 home defeat at the hands of Doncaster Rovers, who climbed to 17th.
Wednesday are now in the bottom three after Yeovil Town's 1-1 draw at Bolton Wanderers lifted them to 21st place.
Ed Upson looked to have given Yeovil all three points with a goal 11 minutes from time, but Alex Baptiste earned his side a point with an equaliser in the 90th minute.
Elsewhere, Millwall won their third successive game after a 2-0 success at home to Leeds United.
Goals from Martyn Woolford and Scott Malone in the 65th and 76th minutes were the difference, as Leeds fell to their third straight league defeat.
