Goals from Shinji Kagawa and Alex Buttner either side of a Jonas Olsson own goal put the champions three goals ahead with barely a third of the 1,500th and final game of Ferguson’s United career played.
James Morrison and halftime substitute Romelu Lukaku reduced the deficit to a single goal with strikes either side of the halftime break but Robin van Persie’s 30th goal of the season and a Javier Hernandez tap-in appeared to have handed the champions a comprehensive win.
But two more goals from Lukaku, whose hat trick spanned just 40 minutes, either side of Youssouf Mulumbu’s strike, gave West Brom a share of the spoils.
It marred the send off for Sir Alex, whose 26-and-a-half years in the United dugout ended shortly before 6 p.m. when referee Michael Oliver blew the whistle on one of the most memorable Premier League matches of all.
Before the match, the Scot had been given a guard of honor by the two sets of players as he entered the pristine Hawthorns pitch on what was a glorious afternoon.
With both home and away fans rising to their feet to give the 71-year-old a standing ovation, he responded by lifting his arms above his head and waving to all parts, including his family in the Cyrille Regis suite.
One of the many Ferguson banners in the away end summed up the feelings of the United fans lucky enough to get tickets for this landmark fixture: ‘For 26 years, you gave us the world’.
Ferguson was not the only giant of British football ending his top-flight career. Paul Scholes, in his 718th and final United game, had a 26-minute cameo that featured a series of tackles that verged on the reckless.
The Hawthorns was a haven for momento collectors, with the match programme, which featured a 38-page tribute to Ferguson, in especially high demand.
For his final game, arguably the greatest British manager in history lived up to his pre-match pledge of selecting a forward-thinking team.
Stalwarts Ryan Giggs, Rio Ferdinand, Nemanja Vidic, Patrice Evra, Paul Scholes, as well as David De Gea, all had to settle for places on the bench as Jonny Evans and Phil Jones formed a youthful center back pairing, left back deputy Alex Buttner made a rare start and Tom Cleverley, Kagawa and Anderson lined up in the midfield four.
One player who was not involved was Wayne Rooney, who is unlikely to have figured even if he had not been given permission to sit out the trip as his wife Coleen is due to give birth to the couple’s second child.
It took just five minutes for Ferguson’s men to demonstrate how they wanted to give the manager the send-off he would have craved.
Hernandez’s pinpoint cross from the right was met by the head of the unmarked Kagawa at the near post.
Three minutes later, United doubled its advantage as the club once again used the full width of the pitch in a manner that has been a hallmark of Ferguson’s Old Trafford tenure.
Antonio Valencia, deputizing at right back, romped forward and his cross-cum shot was deflected into his own net by Olsson.
United’s supporters responded by going through their full repertoire of songs, including the old favorite ‘Let’s all laugh at City’.
In the 30th minute, United went 3-0 up after Buttner seized upon a beautifully weighted pass from Cleverley and sent in a left-footed drive.
Just when it threatened to turn into a humiliation for West Brom, the home side mounted a fightback to place Sir Alex’s winning send off in doubt.