The Hammers came from 2-0 down to beat 10-man Everton 3-2 in added time at Goodison Park thanks to goals from Michail Antonio, Diafra Sakho and Dimitri Payet.
The Hammers hoisted themselves above United and into fifth place thanks to their five-goal thriller and Van Gaal’s were unable to restore their one-point advantage after a 1-0 defeat by West Bromwich Albion on Sunday afternoon.
West Ham face the Red Devils in the FA Cup quarter-final at Old Trafford on Sunday afternoon for a place in the last four.
Former Arsenal and Tottenham Hotspur defender Campbell believes the Hammers can mount a strong top-four challenge in their final nine Premier League games of the season.
“West Ham can gate crash the Champions League places with the way they’ve been playing and the fact teams around them have underperformed,” Campbell told Sportlobster.
“West Ham came from behind to beat Everton at Goodison. It’s a sign of how much belief Bilic has instilled in his side and I think if they keep playing the way they are they will finish above United at the very least.”
West Ham are four points behind fourth-placed Manchester City, who occupy the final Champions League qualifying spot.
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