Manchester United crashed out of the League Cup as West Ham avenged their painful loss to Ole Gunnar Solskjaer's side with a 1-0 win at Old Trafford on Wednesday.
The Hammers suffered a gut-wrenching 2-1 defeat against United in the Premier League on Sunday when David De Gea saved Mark Noble's stoppage-time penalty after Jesse Lingard's late winner.
But David Moyes' men got a measure of revenge three days later as Manuel Lanzini's first half goal dumped United out in the third round.
Solskjaer made 11 changes and Moyes opted for 10 alterations, with West Ham's understudies making the most of their moment in the spotlight.
Ryan Fredericks ghosted past Alex Telles and cut back for Lanzini to sweep past United goalkeeper Dean Henderson in the ninth minute.
That was enough for Moyes to secure a first win over United since they sacked the Scot after less than a season in charge in 2014.
It was also West Ham's first victory at Old Trafford since 2007, earning them a home tie against holders Manchester City in the last 16.
In the photo gallery above, Andy Mitten and Liam Wheeler have provided their player ratings for Manchester United and West Ham respectively.