Patrick van Aanholt scored the winner for Crystal Palace, as they moved out of the Premier League relegation zone with victory over struggling Middlesbrough.
Palace had the better of the first half and deservedly took the lead through the Dutchman’s low drive from the edge of the box – his first goal since joining the club in the January transfer window.
Chasing the game in the second half, Boro’s Cristhian Stuani struck an effort straight at Wayne Hennessey from inside the area, and Fabio sent a shot over the crossbar late on.
The Teessiders have now failed to win in their past nine league games and are 16th in the table, one point above the relegation zone and level on points with their opponents.
The victory for Palace also drops champions Leicester into the relegation zone.
Sakho aids Palace survival hopes
Sam Allardyce had won just once in eight games since taking over as Palace boss in December and questions were being asked about whether he had returned to football too soon after his embarrassing departure from the England job, or been affected by that experience.
Allardyce has never been relegated from the top flight and told Football Focus before the game that the problems at Selhurst Park “were a lot deeper than he had expected”.
But the Eagles collected a priceless win – their third at home this season – to boost their own survival hopes, while pushing managerless Leicester deeper into trouble.
Goalkeeper Hennessey made four comfortable saves as he helped his side to just their second clean sheet of the campaign, but debutant Mamadou Sakho was a towering presence at the back.
The Frenchman, signed on loan from Liverpool in January, was making his first start of the season and in an assured performance, he won the ball back 11 times and made six clearances, which was more than any team-mate.
Boro firing blanks
Aitor Karanka’s side have also won just four games all season, fewer than any other side in the division.
Their biggest problem is scoring goals, having found the net a mere 19 times in 26 games on their return to the Premier League, and this was their third consecutive league game without a goal.
Uruguayan Stuani, who has scored four of those 19, had their best opportunity to claim a point, but his angled shot from inside the area caused Hennessey no problems.
Striker Rudy Gestede was signed from Aston Villa in the transfer window to boost their front line, but the £6m acquisition failed to make an impact after appearing as a half-time substitute.
Having lost against a relegation rival, Boro will be hoping to pick up maximum points against fellow strugglers Swansea, Hull and Bournemouth, who they face in their remaining 13 games.
Man of the match – Mamadou Sakho (Crystal Palace)
‘Our approach was not the best’
Crystal Palace manager Sam Allardyce: “Selhurst Park was rocking today. It felt like they really enjoyed the commitment from the players and really got behind us.
“For me it was all about the quality in the first half we continued to pepper Middlesbrough’s box with crosses and shots and it came to Patrick van Aanholt and he scored with his weaker foot.
“We need that sort of quality if we are going to stay up and he has proved himself with four goals this season now – three for Sunderland, one for us.”
Crystal Palace full-back Patrick Van Aanholt: “I lost my granddad last week. I am very pleased to get the goal for him. Obviously I am very sad to lose him but I thank him a lot.”
Middlesbrough manager Aitor Karanka: “It difficult to lose but we have to keep going.
“This is not the first time I’m living this situation but the only thing I know is to keep working.
“The way we approached the game wasn’t the best. I didn’t need to say how important the game was to win – I think everyone knew.”
Crystal Palace travel to West Brom next Saturday (kick-off 15:00 GMT), while Middlesbrough go to Stoke at the same time.