Off colour Albion get stung by killer Bees; Brentford 3 West Bromwich Albion 0 (Brentford win 4-2 on aggregate).
Brentford captain Jamie Bates and substitute Charlie Oatway turned this first-round tie on its head in the 57th and 59th minutes and to complete Albion's humiliation a second substitute, Lloyd Owusu, fired in a third goal, deep into injury time.
If Albion were trying to get shot of this competition, they could not have done a better job. Why else would they allow Mario Bortolazzi, signed on a free transfer from Genoa last week, to spend two days back home in Italy when he could have been on the bench?
Either that, or Albion thought they had got the job done in the first leg, despite carelessly conceding a late goal in their 2-1 win at The Hawthorns.
A shocked Albion manager Dennis Smith said: "To lose 3-0 to any team, anywhere, is a smack in the mouth. I don't like it. No excuses but the chances we missed in the first leg cost us."
Albion's fans filled a whole stand behind one goal but spent the entire match in subdued embarrassment. They are accustomed to early defeats in the League Cup but this one takes a lot of beating.
Smith's team had received several wake-up calls before Brentford struck, just before the hour. Albion failed to deal with Paul Watson's free kick and Bates rose at the far post to head easily past Alan Miller.
Two minutes later, Albion were rocked again when Watson's cross was flicked on by Andy Scott and Oatway swept in the second goal from close range.
Albion had created one clear-cut chance before Brentford opened the scoring and Lee Hughes missed it. It was his sixth one-on-one against a goalkeeper in the last three games and he has failed to put away any of them. This time, he drove against Jason Pe arcey's legs after Sean Flynn had lobbed the ball over Brentford's defence.
But after Brentford's double strike, Albion failed to get a shot on target. Kevin Kilbane planted a diving header just wide in the 69th minute and Shaun Murphy nodded wastefully over from Kilbane's free kick in the 84th.
It was hard to believe that Albion had gone from bad in the first hal to considerably worse in the second. Gone was the flair, passing and movement they showed at Barnsley on opening day and in the 4-1 rout of Sheffield United last Saturday.
Their failure to cut out balls from either flank cost them two goals in the 2-2 draw at Barnsley and was their downfall again last night. And yet it was the general malaise of Albion's performance that was hard to understand.
Brentford were queuing up with first-half chances, Miller rescuing them in the 10th minute with a diving save from Martin Rowlands. And Albion were reprieved two minutes later when Scott's downward header from Darren Freeman's centre went straight into M iller's grateful arms.
But it was only a matter of time before Brentford broke the deadlock and for all Albion's ineptitude, the Third Division side finished worthy winners. Albion lost Mickey Evans to an ankle injury but it was doubtful if his presence would have made any dif ference.
Scorers: Bates (57) 1-0, Oatway (59) 2-0, Owusu (90) 3-0.
BRENTFORD (3-5-2) Pearcey; Cullip (Oatway 54), Powell, Bates; Boxall, Rowlands, Aspinall, R Quinn, Watson; Freeman (Ratley 86), Scott (Owusu 73). Subs: Dearden, Anderson.
WEST BROMWICH ALBION (4-4-2): Miller; Mardon, Murphy, Carbon, Van Blerk; J Quinn, Flynn, Sneekes, Kilbane; Evans (Quailey 13, Potter 76), Hughes. Subs unused: Crichton, McDermott, Burgess.
Referee: Mr S G Bennett (Orpington)
Bookings: Brentford - Freeman (ungentlemanly conduct), Albion - J Quinn (shirt pulling), Van Blerk (foul), Flynn (dissent)
Albion man of the match: Jason Van Blerk.