Liverpool 1 Barnsley 2: Barnsley's brilliance leaves red-faced Benitez on brink

Championship side knock out Liverpool to leave manager under intense pressure before Tuesday's visit from Inter

Liverpool, who have spent much of the winter seemingly on a mission to heap FA Cup embarrassment on themselves, finally succeeded yesterday. Where Luton and Havant & Waterlooville came close, Barnsley of the Championship went even further and clinched a stunning victory at Anfield to reach the quarter-finals.

It was a shock of substantial proportions and could have repercussions for manager Rafael Benitez, who was already attracting much criticism because of Liverpool's lacklustre performances in the Premier League. Now Tuesday's home Champions' League game against Internazionale takes on even greater significance. Lose the tie and the pressure on the Spaniard will be immense.

Yesterday, Benitez gambled by fielding a weakened team bereft of Fernando Torres and – until the final 15 minutes – Steven Gerrard, and he was rewarded by an ignominious defeat to a team who are 29 places below them in the League pyramid. Dirk Kuyt put Liverpool ahead in the first half but a goal from Stephen Foster and a stoppage-time winner from Brian Howard ensured a famous win for the Yorkshire side.

Simon Davey, the Barnsley manager, described it as his best moment in football. "You always dream of coming to Anfield and winning," he said. "We played a fantastic team and beat them. Hopefully this will be a catalyst for us to kick on in the League. We know we have a good group of players who are still improving but I don't think we'll see the best of them until next season."

Davey's praise was widespread but he made special mention of goalkeeper Luke Steele, who was signed on loan only on Thursday from West Bromwich Albion because of an injury to Heinz Muller and because Tony Warner is cup-tied. "Luke is a good goalkeeper who we knew would do a good job for us. Well he did a bit more than that today. He kept us in the game for long periods and pulled off some world-class saves."

Benitez also applauded the Barnsley goalkeeper but tried to emphasise the positive. "The players worked hard and created many chances," he said. And Inter? "If we create as many chances, we will win," he replied.

For much of yesterday it appeared Liverpool would win too. Kuyt was just wide with a shot after 10 minutes and Peter Crouch was close with a header two minutes later. Yossi Benayoun was also to the fore with two efforts before Liverpool had a real scare when Sami Hyypia was dispossessed in the 29th minute and Istvan Ferenczi was thwarted by Charles Itandje's save. That marked a mini watershed because there was a noticeable upping of the momentum by Liverpool.

Xabi Alonso forced a flying save out of Steele and had another goalbound shot saved, so Barnsley were creaking when the home team took the lead after 32 minutes. Ryan Babel dummied to cut in from the left to throw Bobby Hassell off balance and that was enough to give him the space to cross when he reached the byline. Kuyt had pleaded for a cutback from the Dutchman twice in previous attacks and this time he was heard and he teed up the ball before despatching it with uncharacteristic aplomb.

Anfield sat back to enjoy an easy passage into the last eight, but Barnsley ripped up the script by equalising after 57 minutes. Itandje punched clear under heavy pressure from a free-kick but the ball came back into his area within seconds when Martin Devaney crossed from the right and Foster, a centre-back, headed over and beyond the Liverpool goalkeeper. Cue an assault on the Barnsley goal.

Crouch and Benayoun were halted only by desperate blocks by defenders, Hyypia swung twice and was blocked twice and Benayoun beat two players and almost squeezed in a shot two minutes later. Then, with six minutes to go, Harry Kewell clipped the bar with a shot from the edge of the area.

Davey was praying his team could hang on for a draw but his players refused to listen to his pleas for them to stay back. A stoppage-time raid should have brought a penalty when Howard was brought down by John Arne Riise, but he had barely begun to complain to the referee when the ball came to him again. He dispossessed Alonso and beat Itandje with a low left-foot shot.

Barnsley's fans could barely believe what they were seeing; neither could the Liverpool fans. They booed the players off the pitch and then around a thousand staged a protest. Last night it was against the Americans who own the club. On Tuesday, Benitez could be the target.