Liverpool leapfrog West Ham United in the Premier League after James Collins' 79th minute own goal capped an unlikely second half comeback at Upton Park.
Mark Noble's penalty and Steven Gerrard's own goal, following Glen Johnson's smart opener had looked like taking West Ham into the top six.
But out of nothing, another former player in Joe Cole levelled before substitute Jordan Henderson's low cross in towards Jonjo Shelvy was diverted into his own net by Collins to hand the visitors just their second away win of the season and drop The Hammers into the bottom half for the first time this term.
Having secured qualification for the last-32 of the Europa League in mid-week, Liverpool travelled to West Ham without top scorer Luis Suarez, through suspension as Shelvy led the attack alongside Gerrard and Raheem Sterling.
Matt Taylor and Mohamad Diame, both of whom made impacts from the bench during the win over Chelsea side eight days previous, earned recalls to a Hammers team who after defeating Rafa Benitez's side last weekend, faced increased expectations ahead of the visit of The Reds
But those expectations were tempered after just 11 minutes when former Hammer Johnson was allowed to come off the right-hand touchline untracked, before guiding a right-footed effort into the top corner; his third league goal in as many games against his former side.
The England international almost turned provider minute later after evading Matt Jarvis, but Sterling, who celebrated his 18th birthday on Saturday, missed the target from 12 yards.
In stark contrast to the early weeks in the season, during which Brendan Rodgers' footballing philosophy appeared lost on his Liverpool side, signs the Northern Irishman was beginning to assert his style continued to be apparent against a West Ham side who were struggling to impose their physicality on the visitors.
And as a result, the hosts required a slice of fortune to level the score 10 minutes shy of the interval when Joe Allen was adjudged to have handled Guy Demel's volley, as referee Lee Probert pointed to the penalty spot.
Noble duly converted beyond the despairing dive of Pepe Reina, and the Spaniard was equally as helpless to prevent Gerrard's header from bouncing into his own net, following Jarvis' cross, as West Ham hit the front on the stroke of half-time.
Without a focal point to their attack, the away side found creating clear-cut openings in the second half a tough task, as West Ham, through Carlton Cole, who was providing a decent outlet in attack, looked to add to their lead.
Sterling did force Jussi Jaaskelainen into tipping his dipping effort over the bar in a rare attacking moment for Liverpool as Rodgers' side continued to be held at arms length.
But as James Tomkins was introduced to help see out the points in the final 15 minutes, a second former Upton Park favourite, Cole, helped grab an unlikely equaliser as Sterling fed the 31 year old in the inside right channel of the penalty area, which was emphatically rattled past Jaaskelainen.
And Liverpool capped an unlikely turnaround with 11 minutes left as Henderson's cross looked to find the onrushing Shelvy, but instead deflected in off the outstretched Collins and over Jaaskelainen to propel the away side into the top half as West Ham dropped into the bottom half for the first time this season.