Manchester United strolled to a 2-0 defeat of Manchester City on Sunday to return to the top of the English Premier League and closer to a record-equalling 18th title.
Cristiano Ronaldo's deflected free kick and a superb strike by Carlos Tevez on the stroke of halftime made it a comfortable afternoon at Old Trafford for United who moved three points clear of second-placed Liverpool.
United are on 83 points and have three games left to play to Liverpool's two. Four points from their matches at Wigan Athletic on Wednesday and at home to Arsenal next Saturday would mean they are uncatchable.
Chelsea made sure of finishing at least third with a 4-1 victory against their fellow Champions League semi-final losers Arsenal at the Emirates Stadium.
After United's thrilling Champions League win against Arsenal in midweek they rarely needed to get out of second gear to overcome a disappointing City side. "We didn't play well," United boss Alex Ferguson told Sky Sports. "I think we got a horrible game but City didn't look like scoring."
"It's a hard game at Wigan and we've only got three days to prepare so I'll have to freshen up the team again," added Ferguson, who started with Wayne Rooney on the bench and substituted Ronaldo early in the second half.
Ronaldo appeared less than happy to be taken off.
"Of course he wants to play all the time but I have to look at the bigger picture," said Ferguson, who hopes to have Rio Ferdinand back for the Wigan game after the central defender sat out the derby because of a calf injury.
Any pressure Liverpool's 3-0 win at West Ham United on Saturday put on United soon disappeared as Ronaldo scored his 18th league goal of the season in the 18th minute with a free kick after Dimitar Berbatov had been fouled by Stephen Ireland.
Ronaldo did not strike the ball with his usual venom but it took a deflection and nestled into the corner past the slightly wrong-footed City keeper Shay Given.
Tevez, who was quoted in Sunday's newspapers as saying he wants to leave Old Trafford at the end of the season, was intent on showing United's fans what they might be missing next season.
The livewire Argentine was denied by the woodwork when he cut in and curled a great effort past Given but he was not to be denied again as the halftime whistle approached.
Berbatov controlled a high ball before picking out Tevez who fired an unstoppable shot past Given off the inside of the post.
Chelsea blew away their hangover from Wednesday's last-gasp Champions League knockout against Barcelona by ending Arsenal's 21-match unbeaten league run.
Defender Alex headed them in front and former Arsenal player Nicolas Anelka made it 2-0 at halftime. Kolo Toure's own goal made it 3-0 and although substitute Nicklas Bendtner pulled one back Florent Malouda completed the rout late on.
With two games remaining Chelsea have 77 points, three behind second-placed Liverpool and six behind United. Arsenal are back on 68.