Javier Hernandez and Nani gave United what should have been a comfortable two goal lead, but a Patrice Evra own goal and tap in by Somen Tchoyi gave The Baggies a very surprise share of the points.
Sir Alex Ferguson clearly showed that he picks the team and added more fuel to the media circus while doing so, but that decision had no effects on the outcome - the poor concentration in defense did.
The United manager opted to partner Chicharito with Berbatov and leaving Wayne Rooney on the substitute's bench, so it has nothing to do with that "ankle injury," but rather form and/or the center forward's head is not right at the moment.
Almost as surprising as the exclusion of Rooney, Michael Carrick partnered Anderson in the center of the midfield and Ryan Giggs returned to the starting XI after he has fully recovered from his ever-troubling hamstring.
With no real surprise, the match was played a high-tempo and a frenetic pace, and it was the away team that had the first chance.
James Morrison made a mazing run through the heart of the United midfield and then lofted a teasing ball to the far post, but Chris Brunt could not get much on his header and United escaped the early pressure.
In the fifth minute, Chicharito made a very good run and was fouled by Morrison just 25-yards from goal, which created the first really good opportunity for United.
Nani stepped up to take the free-kick and his swerving effort could only be parried by Scott Carson, and Hernandez showed his predatory skills and pounced to score his first Premier League goal.
There were three chances - one for West Brom and two for United - but somehow the match amazingly stayed at one-nil.
Dimitar played a great through ball to Nani, but hesitation and indecisiveness by the Portuguese winger so the great chance come to nothing.
Then United were lucky to not have conceded, and a big thank you needs to be given to the quick reaction of Rafael, who confidently - or unknowingly - under severe pressure from an onrushing Brunt, directed the pinpoint cross just wide of his post.
From completely nothing, Berbatov decided to have a go from long-range and his effort rooted Carson to his spot, but it curled around the wrong side of the post and West Brom were able to breathe a little easier.
There was no questioning what West Brom set out to do - pump crosses into the area to put pressure on Rio Ferdinand and Nemanja Vidic - because United has proved that they are not very confident at dealing with set pieces or crossing - especially with the big, physical Marc-Antoine Fortuné leading the Roberto Di Matteo's line.
Ryan Giggs made a great 50+ yard run and was dragged down just inches outside of the area by Youssuf Mulumbu, but his curling left-footed effort did not make it passed the wall, but the pressure for United did not stop there.
From the ensuing throw-in, Nani sent a low, driven cross across the face of the West Brom goal, but Chicharito could not manage to get a toe on it.
Berbatov then missed a glorious chance himself to put United two goals to the good after Carrick picked him out and from just about six-yards out, he blasted the ball wide of Carson's left-hand post.
United were finally two goals in front after Nickey Shorey cheaply gave away possession to Nani, and then a wonderful one-two with Berbatov the winger polished off the move with a great left-footed finished.
With United putting their pressure on cruise control, West Brom showed just why they are sitting in sixth place in the Premier League, because they kept the ball well and stroked it around with confidence.
Shorey, Brunt and Morrison combining well, but the latter of the three's shot was just wide of Edwin van der Sar's left-hand post.
United seemed very content to allow the visitors all the possession they wanted and they were waiting to land the all-important killer blow if West Brom made a mistake.
The first yellow card of the day went to Shorey as he was again dispossessed by Nani, and The Baggies defender tried pulling him back for over 10 yards.
Giggs seemed to reaggravated his niggling hamstring and was forced to join Sir Alex on the United bench, and without a winger available at his disposal, the Gaffer was forced took a few minutes to decide how he would reorganized his line-up.
Finally, he brought on Darron Gibson to replace aging Welshman a few minutes later forcing Anderson to go out on the left wing.
Thirty seconds into the second-half, United had a good chance to extend their lead, but Chicharito's header was deflected out for a corner.
West Brom did not do well to clear their lines and Nani was able to clip a cross into the area, but Vidic's well-placed header pinged off the bottom of Carson's right-hand post.
Anderson put United under some unneeded pressure when Somen Tchoyi got the better of him, and from the resulting free-kick West Brom pinged the ball off a couple of defenders and ultimately crossed the line after his glanced off an unsuspecting Evra.
Evra, who should shoulder some of the blame for the build-up to goal, made a great run down the left-hand side and Berbatov pounced but his shot was well blocked by by Gabriel Tamaş.
West Brom were level just a few minutes later when van der Sar clumsily dropped a looping cross from Morrison into the path of Tchoyi and he tapped the ball into the unguarded net.
Gibson earned the first United caution of the match after United needlessly gave the ball away in the attacking third, and forced the midfielder into making a stretching tackle on Tchoyi.
Evra tried to atone for his mistake and his own goal, but Carson did well to tip his shot over his crossbar for a United corner.
Nani won a free-kick in a very dangerous area, but his wayward free-kick ended up in the crowd.
For some odd reason United began to sit back and amazingly allowed West Brom dictated the play.
The luck continued to be with The Baggies as Anderson's left-footed shot was well parried by Carson into a dangerous area, but the ball some how, some way made its way back to the Albion goalkeeper.
To rapturous roar of the three-fourths of the Old Trafford crowd, Ferguson made his final two changes bringing both Paul Scholes and Wayne Rooney on for Carrick and Anderson in hopes to change the fortunes of United.
United were given a gift when the referee, Mike Jones, deemed that Gonzalo Jara made a back-pass to Carson giving United an indirect free-kick 12-yards from The Baggies.
With no trickery, Nani played the ball back into the path of Rooney, but out-of-sorts center forward's tame shot lacked any height and was easily cleared out of danger.
Manchester United played out the rest of the game with impotence and lack the killer instinct that Sir Alex Ferguson was talking about prior to the game, and West Bromwich Albion was fully deserving of their point because they never gave up.
Nani continued to show that he is one of the glowing and most important players at United. It was his free-kick that led to the opening of the scoring and his goal should have sealed the points for the home team, but lack of concentration and carelessness prevented that.
E. van der Sar - 4, Rafael - 6, R. Ferdinand - 7, N. Vidic - 7, P. Evra - 5, Nani - 7, M. Carrick - 6 (P. Scholes - 5), Anderson - 6 (W. Rooney - 5), R. Giggs - 6 (D. Gibson - 5), J. Hernandez - 7, D. Berbatov - 7
J. Hernandez (5'), Nani (25')
Shots (On Target): 20 (6)
Fouls Conceded (Suffered): 10 (10)
Bookings: D. Gibson