(CNN) -- Alex Ferguson was too angry to talk to the press after Manchester United's Champions League exit, and Roberto Mancini was feeling very much the same way after a shock defeat surely ended his side's English title defense on Saturday.
Manchester City crashed 2-0 at Everton, which allowed United to march 15 points clear with just nine games to play following a functional 1-0 win over second-bottom Reading.
Mancini's ire was raised not only by a controversial refereeing decision late in the match -- mirroring Ferguson's frustration after Nani's red card against Real Madrid -- but also by his team's capitulation against a side thrashed by struggling Wigan last time out in the FA Cup.
Everton even had Steven Pienaar sent off with half an hour to play, but the key moment came when Marouane Fellaini's handball inside the area was penalized with a freekick outside of it as City trailed 1-0 with four minutes left.
"He is a bit angry, as you can imagine," Mancini's assistant David Platt said after the match.
"He is just taking stock of the situation and calming down. He doesn't want to come out here and say anything that might get him in trouble."
Platt later told City's website: "From where I was down on the touchline I didn't know if it was inside or not, but we quickly had a message come through to us that it was inside -- having now seen it myself, it was well inside the box, but it's not gone for us.
"But even then we probably created enough decent chances to get something out of the game."
Everton also had an appeal for a penalty turned down when Fellaini fell, and Kevin Mirallas had an effort ruled out for offside.
Even so, goals from midfielder Leon Osman and substitute Nikica Jelavic kept David Moyes' team in sixth place, three points ahead of city rivals Liverpool with a game in hand as the club's manager celebrated 11 years in charge.
More importantly in terms of the Premier League title race, it left United in pole position to claim a record-extending 20th English crown at the expense of their bitter rivals.
Ferguson made eight changes following last weekend's FA Cup draw with Chelsea, but it was two of the players who retained their places that made the difference against managerless Reading.
Center-back Rio Ferdinand charged upfield and directed the ball towards Wayne Rooney, who teed the ball up and then saw his volley balloon over goalkeeper Stuart Taylor after taking a big deflection.
That 21st-minute effort -- Rooney's 12th goal in the league this season and 16th overall -- was enough to see off a visiting team which had sacked manager Brian McDermott last Monday.
Ferdinand has been called up into the England squad for the first time since 2011, and Ferguson confirmed that the 34-year-old would be available for this month's World Cup qualifiers against San Marino and Montenegro despite earlier expressing fears about his fitness.
Ferdinand was omitted by Roy Hodgson for Euro 2012 as the coach cited "footballing reasons" -- though it was widely reported that the United defender missed out due to the fallout from his younger brother Anton's racism case against John Terry, who was selected for the tournament in Poland and Ukraine.
"It wasn't a great performance but where we are now is not down to today, but the last six months," Ferguson said.
"The team has shown great consistency and played a lot of great football. Our goal difference is big over City now -- 13 goals.
"The problem I've got is a lot of players are away on international duty and play two games. They come back and then we've got a lunchtime game against Sunderland on Saturday (March 30) and then it's lunchtime again against Chelsea on the Monday. We have a squad to use it and that's what we did today."
Fifth-placed Arsenal bounced back from the club's midweek Champions League exit with a 2-0 win at Swansea.
Left-back Nacho Monreal scored his first goal since leaving Spanish side Malaga on January's transfer deadline day, and Ivory Coast forward Gervinho also netted as Arsene Wenger's team moved to within two points of fourth-placed Chelsea -- who host London rivals West Ham on Sunday.
Seventh-placed Liverpool crashed 3-1 at Southampton, who moved seven points clear of the relegation zone.
West Brom could have climbed above Brendan Rodgers' former European champions, but drew 0-0 at midtable Stoke.
Aston Villa won for the second match in a row to establish a six-point buffer over the teams in the relegation zone, beating bottom club Queens Park Rangers 3-2.
In Sunday's other matches, third-placed Tottenham will look to bounce back from successive defeats against Liverpool and Inter Milan in the London derby at home to Fulham.
Third-bottom Wigan host Newcastle, while Sunderland will seek to halt a slide down the table at home to 14th-placed Norwich.