A controversial penalty and a touch of brilliance from Luis Suarez handed Liverpool victory over Sunderland.The Black Cats fell behind to a Dirk Kuyt first-half penalty after John Mensah had fouled Jay Spearing.Referee Kevin Friend had awarded a free-kick before pointing to the spot after noting the linesman's decision.Suarez doubled the lead after the break when he powered in from a tight angle before Sunderland's Mensah was shown red for pulling back Suarez.That was the bitter icing of a tasteless cake for Sunderland, who also lost three players during the match because of injuries.The Black Cats will not want to look at the table either. Having now lost five of their last six, Steve Bruce's men may now start looking over their shoulder rather than ahead.Meanwhile, Liverpool will still be hoping to steal the fifth European spot - although they will not be wholly pleased with their performance.Sunderland were the livelier of the teams in the opening 20 minutes and first to the second ball against a side who still seemed to be suffering from the exertions and the disappointment of their midweek Europa League exit.Despite their inability to conjure a threat in open play, Kenny Dalglish's side looked dangerous on set-pieces, especially with £35m giant striker Andy Carroll present up front.Before the penalty, Liverpool had the best chances to take the lead - with the former Newcastle man involved in the first instance.Raul Meireles pinged a corner to the back post which the tall forward nodded back into the six-yard area for Dirk Kuyt.The Dutchman's swept shot goalwards was brilliantly saved point-blank by Simon Mignolet. From the following corner, Kuyt headed over the bar from 12 yards.The Black Cats found space on the wings and managed to despatch the ball into the Liverpool area but more often than not the visiting defence coped easily with what was thrown at them.The one moment they relied on a bit of luck was when Asamoah Gyan and Danny Welbeck combined beautifully down the left before Welbeck swung in a delicious ball across the area, which Kieran Richardson only just failed to get a toe to.It was Richardson's last action of significance, as he came off the pitch to be replaced by Steed Malbranque. The home side had already made one enforced change when they replaced the injured Sulley Muntari with Lee Cattermole.If Sunderland thought their run of bad luck was over, they were made to think again when Liverpool were awarded a penalty.Mensah's poor chest control allowed Spearing to steal before he was brought down by the Sunderland player.Referee Friend pointed to a free-kick before changing his mind, much to the fury of Sunderland boss Bruce on the touchline. But the decision had been made and Kuyt duly placed the ball to the left of Mignolet.The Reds, buoyed by scoring, came close to adding another when Luis Suarez's low half volley had to be palmed away by the Sunderland keeper.The Uruguayan had better luck after the break, although his strike owed more to audacity than fortune.The midfielder was picked out by Kuyt's throw-in on the right and drove down the byline before cheekily thrashing the ball over the head of a crouching Mignolet from the tightest of angles.Up to that point, Sunderland had only managed a couple of curling efforts from Malbranque and Jordan Henderson that failed to trouble keeper Pepe Reina.They had also lost forward Welbeck because of another injury during the second period.And with the eight minutes of the match remaining, Sunderland's miserable day was compounded with the sending off of Mensah for pulling back Suarez, who was through on goal.Source: BBC