Bolton progressed to the last 16 of the Carling Cup after a Jared Borgetti goal earned them victory over West Ham.
The Hammers had the better of the first half with David Bellion impressive, the Frenchman setting up Paul Konchesky who saw his effort ruled out for offside.
The hosts livened up after the break and went ahead when Mexico's all-time leading goalscorer Borgetti headed in a deep cross from Khalilou Fadiga.
Kevin Nolan nodded over soon after but it was enough for Bolton to go through.
Both teams made six changes from their Premiership fixtures at the weekend but both started well, with fringe players keen to make an impact.
Bellion went on a mazy run before seeing Konchesky's clinical finish disallowed, before Abdoulaye Faye made a fine block from Marlon Harewood's shot.
Having failed to create any clear-cut chances before the break Bolton improved, with Martin Djetou controlling their play just in front of the back four.
Stelios Giannakopolous flashed a shot wide before Fadiga forced a fabulous save from Shaka Hislop, just moments before Borgetti put them in front.
Hayden Mullins had a shot parried by Ian Walker as West Ham tried to force a leveller but Bolton hung on.
Bolton manager Sam Allardyce said:
"When you need to be consistent and dig results out and stay at the top, you need to be able to produce a result when you don't play at your best.
"We produced the all-important bit of quality that we needed and that was the only difference between both sides.
"We've not been at our best tonight but we produced that bit of quality."
West Ham manager Alan Pardew said:
"That's twice we've played Bolton now and dominated for almost the entire 90 minutes. But they had a good little spell just before they scored.
"That got us chasing the game but we let ourselves down in the final third.
I felt the strikers could have done better tonight - the rest of the team was spot-on. It's a disappointing night for us."
Bolton: Walker, O'Brien, Ben Haim, Jaidi, Gardner, Faye (Djetou 45), Fernandes (N'Gotty 79), Nolan, Fadiga, Borgetti, Giannakopoulos (Pedersen 59).
Subs Not Used: Jaaskelainen, Nakata.
Booked: Faye, Ben Haim.
Goals: Borgetti 64.
West Ham: Hislop, Repka, Collins, Ward, Konchesky, Bellion, Dailly, Mullins, Clarke (Newton 72), Sheringham (Aliadiere 73), Harewood (Fletcher 86).
Subs Not Used: Bywater, Williams.
Ref: A Marriner (W Midlands).