The Carabao Cup third round shocks continued on Wednesday night as West Ham were dumped out by League One opposition.
The Hammers suffered a 4-0 defeat to Oxford to send them crashing out of the competition just 24 hours after Colchester beat Tottenham on penalties.
Just a few days after Manuel Pellegrini’s side beat United at home they were humbled by the lower league opponents.
The Hammers had a weakened side out but still had the experience of Jack Wilshere and Pablo Zabaleta on the pitch with the likes of Mark Noble and Sebastien Haller on the bench.
After a goalless first half, Elliott Moore opened the scoring for Karl Robinson’s side in the 55th minute before Matty Taylor doubled the lead in the 71st minute.
West Ham had no answer and the defeat was confirmed when Tarique Fosu added a third six minutes from time with a fourth added by Shandon Baptiste in added time.
Liverpool’s victory over MK Dons was far from convincing with a goalkeeping howler by Stuart Moore gifting them a goal in the first half.
Ki-Jana Hoever added a second after the break but Paul Tisdale’s side caused constant problems for the Premier League leaders.
Harvey Elliott impressed on his debut and he hit the woodwork twice in the match.
Chelsea were convincing winners over Grimsby with their 7-1 win at Stamford Bridge.
Ross Barkley opened the scoring after five minutes before Michy Batshuayi added a second just two minutes later.
Matt Green got one back for the away side before they were blown away thanks to goals from Pedro, Reece James, Kurt Zouma, Callum Hudson-Odoi and a second from Batshuayi.
Manchester United also struggled in their third round clash against Rochdale.
Mason Greenwood’s second half goal was cancelled out by Luke Matheson to take the match to penalties.
United had to rely on penalties to reach the fourth round with Daniel James hitting the winning spot kick.
Full results from Wednesday’s third round fixtures:
Brighton 1-3 Aston Villa
Burton 2-0 Bournemouth
Chelsea 7-1 Grimsby
Manchester United 1-1 Rochdale (Man United win 5-3 on penalties)
MK Dons 0-2 Liverpool
Oxford United 4-0 West Ham
Sheffield United 0-1 Sunderland
Wolves 1-1 Reading (Wolves win 4-2 on penalties)