Match ends, West Ham United 1, Sunderland 0.
West Ham extended their unbeaten home run to 13 games with a win over Sunderland, who missed the opportunity to climb out of the relegation zone.
Michail Antonio's first-half goal, his fifth in 15 starts for the club, proved the difference.
The forward weaved into the box and struck low into the bottom corner of Vito Mannone's goal.
Jack Rodwell had the ball in the net for Sunderland in the second half but he handled it in the build-up.
Substitute Rodwell also saw a second effort go over the bar after a superb last-ditch tackle from Hammers full-back Sam Byram, while Andy Carroll's volley smashed off the cross bar at the other end.
It means Sam Allardyce's side remain second from bottom on 23 points, one behind Newcastle and Norwich.
West Ham move up to fifth place on 43 points - their highest total after 27 Premier League games.
A happy home for the Hammers
West Ham have only six home games remaining before their move to the Olympic Stadium and they are making the most of their time left at the Boleyn Ground.
Slaven Bilic's side have won eight and drawn five of their last 13 games on home soil - their last defeat coming against Bournemouth in August.
It was not a performance to remember for the Hammers, off the back of their 5-1 demolition of Blackburn in the FA Cup, but Antonio took his goal superbly in the first half and they withstood a Sunderland revival after the break.
After being gifted the ball by a Patrick van Aanholt error, Antonio scrambled his way past the Sunderland defence and switched to his right foot before curling home.
The hosts were twice denied by the woodwork as well. Mark Noble's first-half strike was palmed on to the bar after a brilliant reflex save from Mannone while Carroll's fierce shot from close range cannoned off the top of the goal.
"They had a couple of chances but if we are counting them, we deserved to win the game," Bilic said.
"I was hoping to score again so we could play more freely but we didn't. We didn't have a great game but we deserved to win and are happy about it."
'We must get over performing but not winning'
Sunderland came into Saturday's game after a two-week break, having beaten Manchester United 2-1 in their last Premier League outing.
Despite a warm-weather training trip to Dubai, the Black Cats looked sluggish in the first-half against the Hammers and failed to register a shot on target.
But they showed spirit after the break, with Jermain Defoe twice volleying wide early after the restart and Rodwell making an instant impact off the bench.
Adrian saved well with his leg after Rodwell's first effort, and the England international then saw his strike from close range ricochet off the goalkeeper and on to his arm.
And manager Sam Allardyce, on his return to his former club, was left frustrated by the missed chances.
"The bottom line is we haven't scored. Not converting chances is costly and it's a victory lost on chances created," said Allardyce. "Getting back in the game and getting the draw was at least what we deserved.
"We've got to get results. We have to catch up as we have no chance otherwise. We've got to get over this trait of performing but not winning."
Man of the match - Michail Antonio
The stats you need to know
- Michail Antonio has scored in each of his last three games at Upton Park in all competitions.
- Vito Mannone has conceded in all 10 of his appearances for Sunderland this season in all competitions (18 goals).
- The woodwork was hit three times during the game, the joint-most in a Premier League game this season.
- West Ham have conceded just four goals in their last eight home games, keeping five clean sheets in that spell.
West Ham welcome Tottenham on Wednesday, while Sunderland host Crystal Palace on Tuesday (both 19:45 GMT)
- 22ByramBooked at 71mins
- 16NobleSubstituted forObiangat 82'minutes
- 28LanziniSubstituted forMosesat 65'minutes
- 29EmenikeSubstituted forCarrollat 59'minutes
- 3van Aanholt
- 6CattermoleSubstituted forRodwellat 65'minutes
- Mike Dean
- Shots on Target
Second Half ends, West Ham United 1, Sunderland 0.
Foul by Dimitri Payet (West Ham United).
Dame N'Doye (Sunderland) wins a free kick in the defensive half.
Foul by Pedro Obiang (West Ham United).
Jack Rodwell (Sunderland) wins a free kick in the attacking half.
Foul by Andy Carroll (West Ham United).
John O'Shea (Sunderland) wins a free kick in the defensive half.
James Collins (West Ham United) wins a free kick in the defensive half.
Foul by Jack Rodwell (Sunderland).
Corner, Sunderland. Conceded by Andy Carroll.
Foul by Aaron Cresswell (West Ham United).
Dame N'Doye (Sunderland) wins a free kick in the attacking half.
Attempt missed. Dimitri Payet (West Ham United) left footed shot from outside the box is close, but misses to the right. Assisted by Victor Moses with a headed pass.
Substitution, West Ham United. Pedro Obiang replaces Mark Noble.
Andy Carroll (West Ham United) wins a free kick on the right wing.
Foul by John O'Shea (Sunderland).
Attempt saved. Jack Rodwell (Sunderland) header from the centre of the box is saved in the top centre of the goal. Assisted by Wahbi Khazri.
Attempt saved. Dame N'Doye (Sunderland) right footed shot from the left side of the box is saved in the centre of the goal. Assisted by Jan Kirchhoff.
Attempt missed. John O'Shea (Sunderland) header from the right side of the six yard box is close, but misses to the right. Assisted by Wahbi Khazri with a cross following a corner.