Both managers were facing their former clubs and how the ex-Hammers striker would have liked to have kicked off his Charlton managerial career with an opening day victory at Upton Park. For fifty minutes, despite being down to ten men, Dowie still looked set to take three points back to the Valley thanks to that Bent spot kick, before the wheels well and truly fell off the Addicks wagon. The new Charlton boss fielded four fresh faces in his starting line-up, Djimi Traore, Amady Faye, Jimmy Floyd Hasselbaink and Scott Carson each made their debuts while Andy Reid was left on the bench.
Having hardly got the ball out of their own half in the opening quarter of an hour there appeared to be little danger when a rare Addicks attack saw Bryan Hughes float a hopeful cross towards no mans land but Danny Gabbidon carelessly handled as Hasselbaink ghosted towards the far post.
After consulting his assistant - who has somehow given a corner - referee Howard Webb pointed to the spot and Bent calmly blasted the penalty to the right of the so far redundant Roy Carroll to give Charlton an unlikely lead.
Midway through the half however, Dowie's delight turned to despair, when Traore was booked twice in three minutes for scything through Lee Bowyer, and then encroaching as the Hammers midfielder attempted to take another free kick.
Pardew's men had already kept Carson busy and as they went in search of a leveller, they thought they had got it on the half hour mark when Marlon Harewood bundled home after the on-loan Liverpool keeper had pawed Zamora's point blank header skywards.
But referee Webb ruled the effort out for Harewood's push and with debutant Tyrone Mears unluckily sending a 25-yard screamer just the wrong side of the post, Charlton still managed to make it to the interval with their noses in front.
Six minutes into the second half however, West Ham inevitably drew level when Bowyer whipped a low cross into the six-yard box for the industrious Zamora to tap home at the far post.
In reply, Talal El Karkouri saw Carroll forced into a double save as he beat out his thunderous 35-yard free kick and then saved Bent's follow-up, but, by now, Charlton were firmly on the back foot. And midway through the half, Bowyer and Zamora combined again to put Hammers deservedly ahead.
This time, the former Charlton, Leeds United and Newcastle United midfielder turned inside Bryan Hughes on the edge of the six-yard box and although Zamora could only scuff his shot goalwards, he still beat Hermann Hreidarsson, who saw the bobbling effort bounce agonisingly off Carson's left-hand post and then creep over the goal line.
Following his controversial summer return to Upton Park, man of the match Bowyer had already started to win over the sceptical Hammers fans left with sour memories of his dismal 11-game showing during the relegation bound 2002-2003 season.
And after hitting the base of Carson's left-hand post, the workaholic midfielder then went another step to mending those bridges with his third assist of the afternoon with only seconds remaining.
This time, moments after stepping off the bench, it was debutant Cole who was sent clear to slot past the helplessly exposed Carson and confirm a Hammers victory.