Manchester United thrashed West Ham 4-1 at Old Trafford to move three points clear at the top of the Premier League.
Ronaldo scored twice and Carlos Tevez netted a third before Dean Ashton pulled one back for the visitors.
Nani was sent off for head-butting West Ham's Lucas Neill, but after the break Michael Carrick scored United's fourth.
Elsewhere, Fulham edged towards the Premier League safety zone with a 2-0 win over Birmingham, leaving their opponents facing relegation.
Saturday's other results
Bolton 2-0 Sunderland
Aston Villa 0-2 Wigan
Middlesbrough 2-0 Portsmouth
Reading 0-1 Tottenham
Goals from Brian McBride and Erik Nevland saw Fulham move out of the bottom three, putting even more pressure on Birmingham ahead of their last home game against Blackburn.
Firmly stuck at the bottom of the table, Derby have now made it into the history books for all the wrong reasons after Blackburn came from behind to beat them 3-1.
With just 11 points so far this season and only one match left to play, the Rams have now officially picked up the lowest number of points in Premier League history.