Even with an estimated #100million of talent on the pitch at the final whistle as Roberto Mancini threw on James Milner and David Silva, City were unable to force an equaliser.
Milner came closest in stoppage time when Boaz Myhill made a flying save to ensure a West Brom side showing 10 changes from the team which beat Birmingham on Saturday preserved a lead Gianni Zuiverloon and Simon Cox had given them in a two-minute second-half spell.
It was a dismal result for Mancini, who must now try to avoid defeat to Chelsea at Eastlands on Saturday to stop questions being asked about his admittedly short Blues reign.
In fact, as they contemplated their fate on the journey back up the M6, probably the only man who could look back on the contest with any satisfaction was goalkeeper Shay Given.
At the weekend Given admitted his plight at Eastlands was not an attractive one but the Irishman turned in an excellent display, with two saves in particular standing out.
The first, to deny Graham Dorrans needed agility after the midfielder had let fly from 20 yards with a shot heading for the bottom corner.
Then it was strength, speed and dexterity as Given turned away Giles Barnes' header, then got across his goal quickly enough to repel Somen Tchoyi.
Even as he reflected on those efforts at half-time, Given must have known his involvement against Chelsea on Saturday would come from the bench given Mancini's line-up, containing three new faces and three teenagers, had both eyes on the visit of Carlo Ancelotti's men.
In the final analysis, it may be pointed out to Mancini that his purposes might have been better served had this been the game when he selected all his stars.
After all, unless the Italian is harbouring serious ambitions of winning the title, even though City are already seven points adrift of the leaders, a home game against Chelsea is probably not going to make or break their top four aspirations in the same way this defeat ended their hopes of winning a trophy before May.
But at half-time Mancini must have been fairly pleased with himself after Jo had once again rewarded his manager's faith and patience.
The #17million Brazilian scored his first City goal in almost two years in Salzburg last week.
Rather like London buses, once one arrives, another follows shortly afterwards.
Given West Brom controlled so much of the contest, it should be no surprise City pounced on the counter-attack with one of the debutants, John Guidetti, playing a key role before Jo calmly stroked the ball home.
When Given stood tall to beat away a Barnes effort after the midfielder had been sent racing beyond the City defence, it appeared the script for the evening had been written.
Faced with such adversity, West Brom's mood was impressively defiant.
And although Ben Mee was fuming at being on the wrong end of an apparent push in the build-up, there was no doubting the touch of class from Zuiverloon as he belted his side level from 20 yards.
Within a couple of minutes, the Baggies were celebrating again as Cox found the same bottom corner after finding himself some space on the edge of the City box.
The swift reversal in fortune was no more than West Brom deserved and triggered the introduction of Milner in a clear effort to try to salvage the contest.
Silva soon followed but it was all to no avail as the Baggies celebrated a famous win.