PREM: West Ham 0-1 Wolves
Nuno Espirito Santo celebrates the 1-0 away win at West Ham
Substitute Adama Traore's injury-time strike inflicted a fourth straight Premier League defeat on West Ham as Wolves secured a 1-0 victory at the London Stadium.
In what was a tight affair, the hosts were heading for their first point of the season but Traore capitalised on Carlos Sanchez's error in the third minute of injury time to hand Nuno Espirito Santo's side their first top-flight win since beating QPR in February 2012.
A first league win of the campaign sees Wolves move up to ninth in the table, while West Ham, who have only once before lost their opening four league matches of a season, stay rooted at the foot of the league and without a point heading into the international break.
Both goalkeepers were called into action early as Rui Patricio got down low to his right to keep out Felipe Anderson's effort, while Lukasz Fabianski had to be alert to tip Matt Doherty's powerful strike over the bar.
Despite the early saves, chances proved hard to come by at the London Stadium. Robert Snodgrass' shot hit the side netting in the 31st minute but it was one of only a few bright spots for the hosts in the first half.
Wolves looked confident in possession but they too struggled to create any clearcut openings as Raul Jimenez and Joao Moutinho sent efforts wide of the target.
Pellegrini changed things around at the break, replacing Snodgrass with summer signing Andriy Yarmolenko and West Ham almost found a way through. A clever flick from Jack Wilshere found Marko Arnautovic but the Austria international could only prod the ball wide.
Moments later, Patricio was at full stretch, diving away to his right to claw Michail Antonio's looping header off the line.
Wolves then went close to taking the lead in the 74th minute but this time it was Fabianski who kept the scores level, racing off his line to block substitute Leo Bonatini's shot.
They went even closer five minutes later. Ruben Neves' cross-field pass picked out Doherty, who picked out Jimenez in acres of space in the West Ham penalty area. However, the striker, under no pressure whatsoever, missed his kick in front of goal.
Arnautovic almost snatched all three points at the death as he turned inside Conor Coady but luckily for Wolves, the Austrian's shot was kept out by the face of Patricio.
There was still time for one final chance and it fell to Wolves. Sanchez lost the ball deep in his own half before Bonatini teed up Traore, who secured all three points for his side.