West Ham boss Avram Grant hailed an "unbelievable" result as holders Manchester United were dumped out of the Carling Cup with a 4-0 thrashing at Upton Park.
Jonathan Spector and Carlton Cole scored two goals each as United crashed to their heaviest defeat since 2001 and their first loss of the season.
The Hammers are in the semi-final finals of the League Cup for the first time in over 20 years and Grant hopes the result can help inspire a move out of the Barclays Premier League relegation zone.
"I thought we could win but this is still an unbelievable result. We continue our progress," he said.
"We scored four goals and could have scored more. But for me four is enough.
"To be in the semi-finals is very good for this club. We are trying to build something step by step. We have done the right thing.
"We have played many more good games without winning so the players maybe have lost confidence.
"But the most important is to show mental strength and tonight was so unbelievable.
"The gap at the bottom of the Premier League was five points and is now three points.
"We have many games left and I'm sure that this shows we can be good in the future."
Grant praised man of the match Spector and Cole, who has been criticised for his form in recent weeks.
"Spector is a good professional and always tries hard. I changed his position in training to midfield," said Grant.
"I think that he saw the Barcelona performance against Madrid last night and thought that he can do that as well!
"For Cole the best way to do things is to do it on the pitch. Cole worked hard from the first minute and he knows how to do it.
"Every striker has bad times but you need to look back at the end of the season to see how he coped."
The defeat marked the end of United's 29-match unbeaten run and Sir Alex Ferguson was angry with the manner in which his side conceded the goals.
West Ham had an early goal by Victor Obinna correctly ruled out for offside, but they were incensed and Ferguson felt the perceived sense of injustice provided inspiration.
"I didn't expect that, that's for sure. If you analyse it the goals we gave away were absolutely too soft," he told MUTV.
"We didn't expect that, they were terrible goals for us.
"We had one or two half chances and Gabriel Obertan had a shot saved by the goalkeeper (Robert Green) which then hit the post.
"The goals killed it. You can't just give goals away at this level.
"That first goal was a break for them. We were in control in the early part, played some good football. But goals change games.
"The thing that sparked it was the goal that was disallowed because it got the crowd up.
"It was clearly offside because it came off one of their players into the net.
"It was clearly offside but they celebrated for so long. It spurred them up."