Ben May scored deep in extra-time as Colchester pulled off a shock win over West Brom in the Carling Cup.
Fagan scored with a thunderous strike
The Baggies had forced the extra half-hour after Geoff Horsfield's strike cancelled out a Craig Fagan rocket.
But the Premiership side, who had rested some of their star names, were outplayed for much of the game.
Jason Koumas almost snatched victory for the visitors in normal time but May won it for the U's after a goalmouth scramble two minutes from the end.
West Brom boss Megson left out Kanu and Robert
Earnshaw, while Neil Clement was suspended.
And Colchester took advantage early on with Joey Keith firing just over the bar following Richard Garcia's right-wing cross.
Fagan forced Tomasz Kuszczak into a smart save at his near post before firing a fierce drive into the top right corner after some neat footwork on the edge of the area.
Gary Megson's side were offering little themselves and almost fell further behind when Kuszczac acrobatically denied Neil Danns.
The Premiership strugglers enjoyed a rare period of pressure after the break and Horsfield finished with aplomb after Thomas Gaardsoe's raking ball from the back.
Horsfield fluffed another chance when Lloyd Dyer burst into the area five minutes later.
Garcia saw a shot well blocked by Kuszczak before Scott Dobie was denied by Davison at the other end as chances came thick and fast towards the end of 90 minutes.
Koumas saw Davison tip his vicious 20-yard drive wide of the left-hand upright and that was the closest Albion came to preventing the U's from claiming a famous victory.
Colchester: Davison, Baldwin, Chilvers (Halford 59), Brown,
Hunt, Garcia, Danns, Watson, Keith, Fagan (May 73),
Williams (Bowry 91).
Subs Not Used: Cade, Gerken.
Goals: Fagan 29, May 118.
West Brom: Kuszczak, Gaardsoe, Moore, Albrechtsen,
Contra (O'Connor 74), Scimeca, Koumas, Gera (Greening 64),
Dyer, Horsfield, Dobie (Hulse 98).
Subs Not Used: Murphy, Sakiri.
Booked: Gaardsoe, Scimeca, Greening.
Goals: Horsfield 50.
Ref: A Kaye (W Yorkshire).