The Portugal winger latched on to a pass from Wayne Rooney, and his low shot squirmed past Derby goalkeeper Roy Carroll from the left edge of the penalty area.

Paul Jewell's side frustrated the champions for large periods of the game, and United goalkeeper Ben Foster produced a spectacular save from Rams striker Kenny Miller moments before half-time.

But Ronaldo eventually broke the deadlock in the 76th minute, which ensured Sir Alex Ferguson's side moved ahead of Arsenal on goal difference - having played one game one less.

Middlesbrough striker Jeremie Aliadiere came back to haunt his former club as Arsene Wenger's side's title bid was hit by a 1-1 draw in the late kick-off at the Emirates Stadium.

Aliadiere gave Gareth Southgate's visitors the lead in the 25th minute, after he steered Tuncay Sanli's cross past goalkeeper Manuel Almunia.

Arsenal equalised in the 86th minute when Kolo Toure headed in a Cesc Fabregas corner.

Boro striker Mido was shown a red card two minutes from time for a foul on defender Gael Clichy, but the visitors held on to claim a point.

John Terry gave Chelsea a 1-0 victory over Sunderland as the Blues narrowed the gap to second place to three points with a game in hand.

Frank Lampard delivered a dangerous inswinging corner from the left which was met by the Chelsea captain in the 10th minute at the Stadium of Light.

Terry directed a downward header through a crowd of players and past Black Cats goalkeeper Craig Gordon.

Fernando Torres' 20th Premier League goal of the season helped Liverpool consolidate fourth place with a 2-1 win over Reading.

Reading midfielder Marek Matejovsky broke the deadlock in the fifth minute at Anfield when he lashed a half-volley past a static Jose Reina and into the top-left corner.

Javier Mascherano equalised in equally spectacular fashion in the 19th minute, his first goal in a Liverpool shirt with a powerfully-struck shot from the edge of the penalty area.

Torres made the points safe when he headed a Steven Gerrard free-kick past goalkeeper Marcus Hahnemann from close range three minutes after the break.

An 11th-minute strike from Jermain Defoe and a Nigel Reo-Coker own-goal gave Portsmouth a 2-0 win over Aston Villa at Fratton Park.

Defoe controlled a long ball from Glen Johnson before he deftly lobbed the ball over Villa goalkeeper Scott Carson from the right edge of the penalty area.

Reo-Coker scored Pompey's second, directing the ball past Carson from 30 yards out in the 38th minute. Portsmouth midfielder Sulley Muntari and Aston Villa's Olof Mellberg were both sent off late in the game.

Freddie Sears headed a winner nine minutes from time on his debut to give West Ham a 2-1 margin over Blackburn at Upton Park.

Rovers striker Roque Santa Cruz gave Mark Hughes' side the lead in the 19th minute when he glanced a header from a Morten Gamst Pedersen cross past Robert Green.

Dean Ashton equalised in the 39th minute, spinning away from the Blackburn defence on the edge of the area before chipping the ball over Brad Friedel.

Striker Sears, who replaced Nolberto Solano in the 75th minute, saw his shot from 12 yards saved by Friedel but was able to nod the rebound home.