West Ham manager David Moyes has revealed he is ‘thrilled’ with their performance as they beat Sheff Utd away from home.
The first half was goalless despite numerous big chances for both teams.
George Baldock could have put the Blades ahead early on, while Tomas Soucek came close soon after.
Haller scored his second league goal of the campaign in the 56th-minute.
The Ivory Coast international picked up the ball near the edge of the box and fired into the top corner, past keeper Aaron Ramsdale.
Speaking after the victory, Moyes told reporters: “I am thrilled to pick up three points. They have a lot of good players, a good manager – I know what it is like, when you get into a losing run.
“Our boys at the moment are playing with a lot of confidence and thankfully we got another win today.
“I hope we can play even better. Eighth is great at the moment, I hope we can look towards the top and not the bottom as we have done too often.
“We are not going to get too carried away, but in the dressing room there is a great spirit. We have changed a lot of things behind the scenes and the players are buying into it.
“We have to make sure the players enjoy their work and work that will help us in the games.”
The victory is their second in a row after they beat Fulham just before the international break.
Moyes’ side are looking assured in defence and dangerous going forward. Soucek has been a great performer in central midfield alongside Declan Rice.
The Hammers did miss Michail Antonio’s runs today but Haller did well to deputise. His goal was vital in pushing them up the Premier League table.