Sam Allardyce's men had the upper hand from the start and outplayed United with their physical style.
The opening goal came in typical West Ham fashion after Andy Carroll nodded down Matt Jarvis' cross for Vaz Te to head past David De Gea from close range. However, United fought back and grabbed an equaliser via Antonio Valencia, who tucked in an easy finish after Shinji Kagawa showed excellent footwork down the left to penetrate down the touch line with a shimmying run into the box.
West Ham regained the upper hand shortly in the second half when Mohamed Diame curled a beautiful shot past De Gea from the edge of the box with his left foot. The Hammers ultimately failed to hold onto their lead after Robin Van Persie struck home in controversial fashion. The Dutch striker was in an offside position when he pounced onto a Kagawa shot which ricocheted off both posts.
Jussi Jaaskelainen - 6.5
The veteran goalkeeper showed excellent instincts to keep out several close-range shots from the United strikers. He was bailed out by O'Neil, who cleared a goal-bound shot off the line.
Guy Demel - 6.5
The right back had little to do due to United's lack of a real left winger and supported their attack when needed.
James Collins - 7.5
Collins put in a mammoth performance in defence, putting his body on the line to block shots and clearing off the headers that went into the box. United would have had a lot more chances if not for his presence in the heart of defence. His long passes from defence also helped West Ham launch many of their counter-attacks.
Winston Reid - 6
Reid was outsmarted by Kagawa for United's opening goal but he had an average game otherwise.
Joey O'Brien - 7.5
The Irishmen impressed down the flank facing the combination of Rafael and Valencia. He showed that he had the speed to match either of them in defence and managed to find the time for the ocassional foray up front to support the attack.
Mohamed Diame (Off 82') - 8
Diame was always making the dangerous runs into space in midfield to pull United's midfield line out of shape and link up play into the final third. He grabbed a deserving cracker of a goal with a sweet left foot finish which curled in at the far post that left De Gea little chance of saving it.
Kevin Nolan (Off 82') - 6
The West Ham captain made his presence felt with crunching tackles in midfield but went down easily when challenged. He made a few good runs but contributed little in the final third.
Gary O'Neil (Off 68') - 6
O'Neil sat deep and protected his back four well - this was partly due to Rooney having a poor game but he should deserved credit for a hardworking performance. However, he lost track of Kagawa too often and the Japanese midfielder capitalised on it.
Matt Jarvis - 7.5
Jarvis' crosses were always dangerous and always causing problems for United with each of it seemingly pre-programmed to find Carroll like a heat-seeking missile. He managed to shrug off the attention of Rafael and Valencia down the flank - not the easiest task for a winger.
Ricardo Vaz Te - 7
Vaz Te had large periods of anonymity but appeared when it mattered by scoring the first goal and starting off the move that ended up as his side's second goal.
Andy Carroll - 8
Carroll was clearly the best player on the pitch and would have had a higher rating if not for his excessive physical play. He was a constant thorn in United's defence with his physical presence and he contributed defensively with a few last-ditch tackles as well. However, his also showed his darker side with a needless wrecking-ball challenge on Rooney, De Gea and Evra towards the end of the half and several over-the-top challenges on Vidic.
Mark Noble (On 68') - 6
Noble came on to put in more effort in midfield for the tiring O'Neil.
Matthew Taylor (On 82') - N/A
Jack Collison (On 82') - N/A
David De Gea - 7
Despite conceding two goals, De Gea's performance would be an encouraging one for United fans. He showed that he wasn't afraid of the physical side of the game by confidently coming out to claim crosses despite Carroll threatening to flatten him in every other set piece.
Rafael Da Silva - 6
Rafael struggled to cope with Jarvis and provided little going forward. Full of enthusiasm, but little end result from the Brazilian.
Rio Ferdinand - 6
Ferdinand had a tough game in defence against West Ham's barrage of crosses but improved as the game went on. Not the best performance from him, though.
Nemanja Vidic - 7.5
United could have easily lost the game if not for Vidic's effort in winning the headers off Carroll. He was unafraid of challenging the big Englishmen in the air and came away with several body bruises, which only served to typify the effort which earned the Serbian his reputation as a hardman in defence.
Patrice Evra - 6
Evra was a target for Carroll at the far post and fell victim as the striker got the better of him in the air to set up West Ham's first goal. Evra went forward and provided width for United due to the lack of a left winger - not an easy effort for the 31-year-old.
Phil Jones - 5.5
Jones' role in the game to break up attacks had little effect as West Ham effectively bypassed him by lobbing balls into the box. It wasn't that he had a bad game - he was simply played out of it by Allardyce's tactics.
Michael Carrick - 6.5
Carrick provided a passing option for his side and served to close down the space in midfield with a few good tackles to cover up for Rooney losing the ball.
Antonio Valencia - 6.5
Valencia scored a goal but that was about the only positive aspect to his game. His crosses were abysmal and frequently blocked by O'Brien at the back. Those which went through were horribly inaccurate and provided little threat to West Ham.
Wayne Rooney (Off 71') - 4
Rooney was sloppy in possession with many misplaced passes and poor in defence, where he lost track of Diame for West Ham's second goal. He looked unsure most of the time and let his side down, especially since he was handed the important role of having to link up his side's attack. At this rate, Paris Saint-Germain might actually lose interest in signing him.
Shinji Kagawa (Off 78') - 7.5
Kagawa was United's best player in attack with darting runs and short passes to move the ball around the box. He was involved in both goals with smart movement to keep the ball in West Ham's box - a summary of his strength as an attacking player.
Robin Van Persie - 7
Van Persie was clearly far from his top form against West Ham's physical defence but did well enough to create chances out of poor passes into the West Ham half. He grabbed his second goal in two games in controversial fashion after pouncing on a loose ball from an offside position.
Ryan Giggs (On 71') - 7
Giggs came on and helped settle down the midfield with steady passing and runs into wide areas, but it was to little effect as West Ham held strong.
Javier Hernandez (On 78') - N/A