Manchester United stretched their lead at the top of the Premier League to six points after a comfortable 2-0 win at Middlesbrough.
Ji Sung Park then made the game safe in the second half, finishing well after a superb ball from Wayne Rooney.
Sir Alex Ferguson's side are now six points clear of Liverpool, having played the same number of games.
Chelsea opened the scoring against west London rivals Fulham within a minute - Nicolas Anelka finishing a lovely off a lovely passing move.
Anelka broke clear on the right flank and slipped a perfect ball into the path of the Ivorian who took one touch before slotting the ball beyond the advancing Mark Schwarzer.
Bendtner slotted his second from the penalty spot after Sean Davis was adjudged to have brought down Andrey Arshavin.
Arsenal made it 3-0 on 56 minutes. The ball broke for Carlos Vela on the left side of the Pompey area after Arshavin's shot was blocked by Mullins.
The Mexican forward showed Pompey how to finish with a low strike into the far corner.
The home side finished the game with ten men after Noe Pamorot was sent off.
Tottenham maintained their excellent home form with a 1-0 win over West Bromwich Albion.
Manchester City beat Blackburn 3-1 at Eastlands. Striker Felipe Caicedo notched the first on 27 minutes before Robinho stroked home from inside the area seven minutes later.
Elano then slotted home a penalty after Gaël Givet was adjudged to have handled in the area.
Rovers won a penalty when Nedum Onuoha played Pedersen rather than the ball as he tried to clear.
Given saved Diouf's spot-kick and the Senegal man's follow-up. But his luck finally ran out when Andrews arrived to send his first touch over the line.
Diego Tristan scored the only goal as West Ham beat Stoke at The Britannia.
Wigan and Bolton drew 0-0 at the JJB Stadium.