Gary Neville highlighted Manchester United's inconsistency as their biggest problem just seconds before West Ham struck.
United put in a dismal effort in the first 45 minutes at the London Stadium, barely stringing a pass together.
Despite Ole Gunnar Solskjaer resting David De Gea, Bruno Fernandes and Marcus Rashford, the United boss still fielded a side that contained Paul Pogba, Donny van de Beek, Anthony Martial and Edinson Cavani.
But it was a poor showing in front of the 2000 returning West Ham fans.
And it was enough for Neville, in co-commentary for Sky Sports, to voice his displeasure.
"They just can't produce consistency this Manchester United team, the squad," he said.
"There's no rhythm from week to week. You think 'OK we're getting somewhere then next week you think 'Ooh, back to square one'.
"But it feels like it's like that every three days.
"You still fancy in the second half they'll come out and score one or two goals. We've seen it too often."
Seconds later West Ham hit their visitors with a hammer blow.
Tomas Soucek headed home from a West Ham corner and put his side in front.
Neville added: "To only be one goal behind having played this badly will be cause for celebration at half-time"
