Queens Park Rangers replace Scunthorpe in 23rd after their 2-1 loss to Plymouth - for whom Sylvan Ebanks-Blake hit a brace. Preston drop to 22nd to occupy the final relegation spot, with Colchester still bottom.
The Us were indebted to their keeper Dean Gerken for securing a point against Southampton. Jhon Viafara gave the Saints an early lead, but Clive Platt earned the Essex side a point.
Gerken produced three wonder saves in the second-half to claim a precious point for Geraint Williams' men.
United also moved above Norwich and Sheffield Wednesday.
The Canaries had to settle for a point in a 1-1 draw with Charlton Athletic, even though the had to play with 10 men for most of the game.
David Marshall appeared to have Zhi Zheng's shot covered, but the ball sneaked under his arms to give Charlton the lead midway through the first-half.
The visitors were reduced to ten men when Sam Sodje was dismissed for a two-footed tackle on Darel Russell, but a well-organised defence and a superb Nicky Weaver kept Norwich out until the 73rd minute when Russell equalised with a glancing header from Darren Huckerby's left-wing corner.
A goal apiece within the space of two minutes ensured a share of the Boxing Day spoils in the Roses clash between Burnley and Wednesday.
The Owls took the lead after 28 minutes with a penalty kick awarded by an assistant referee who adjudged that Gary Caldwell had brought down Deon Burton in the box.
But that was just the beginning of the drama as goalkeeper Gabor Kiraly took an age to get himself ready for the penalty kick, which enabled referee Scott Mathieson to eventually blow his whistle, a signal for Burton to stroke the ball into a virtually unguarded net.
Tthe home side's response was immediate as David Unsworth swung a cross to the far post where Wade Elliott headed the ball back across goal for Robbie whose header was kept out by goalkeeper Lee Grant only for ex-Sheffield United striker Ade Akinbiyi to convert the rebound from close range.
Goals by Richard Stearman and Patrick Kisnorbo helped Leicester City to only their third home win of the season, as they beat Ipswich Town 2-0 to move out of the bottom three.
Both strikes were the results of set-pieces with the Tractor Boys' defence unable to cope with free-kicks expertly delivered by captain Stephen Clemence.
Roman Bednar helped himself to his own Magnificent Seven to help fire West Bromwich Albion back to the top of the table.
Bednar's seventh goal in seven games, a stunning strike by Robert Koren and a double from Kevin Phillips - all in the space of 28 second-half minutes - saw off promotion rivals Bristol City, who had won three of their previous four games.
Jobi McAnuff got Watford out of jail with a dramatic strike deep into stoppage-time to deny Cardiff City a deserved belated Christmas present at Vicarage Road.
The equaliser prompted completely contrasting reactions from the two managers. While Aidy Boothroyd was embarking on a 20-yard touchline sprint to celebrate with his players, Dave Jones berated the official, pointing to his watch. He had a point.
The goal came in the fourth of what were supposed to be three minutes of stoppage time and it was rough on his Bluebirds, who were the better side and looked set to withstand an aerial bombardment in the closing stages.
Liam Lawrence was Stoke City's hero as he grabbed a controversial hat-trick to send the Potters into third spot in the table while Barnsley kept their unbeaten home run going after a 3-3 draw at Oakwell.
Two of Lawrence's goals came from the penalty spot - the second six minutes into stoppage time - as Barnsley finished the match with ten men.
In a furious finish Steve Foster was red carded late on and, after the game, Stoke youngster Ryan Shawcross - on loan from Manchester United - was spoken to by the police for allegedly inciting the crowd.
Bryan Robson's Sheffield United side were booed off the pitch after missing a hatful of chances as 10-man Blackpool battled back to snatch a point.
James Beattie had grabbed his 13th goal of the season in the 23rd minute, having earlier missed a penalty awarded for a pull on former Scunthorpe striker Billy Sharp.
But the Blades failed to kill off the Bloomfield Road side who hit back midway through the second-half through Claus Jorgenson.
Crystal Palace claimed a comfortable three points from their trip to Coventry thanks to second-half strikes from Clinton Morrison and Paul Ifill.
Morrison slotted home just after the break, before Ifill scored with his first touch after coming on as a late sub to seal the 2-0 victory.
Hull City cruised to a 2-0 victory at the KC Stadium thanks to a dominant second-half display against Wolves.
Goals from Richard Garcia on 47 minutes and Fraizer Campbell on 61 left a jaded Wolves without a win in five games.