Ospreys' second string pulled off a stunning victory at Bath to cement their place at the top of Pool A in the EDF Energy Cup.

The absence of several Test match stars meant only four of the starting line-up from last week's demolition of Gloucester started, and the visitors showed far more appetite than lacklustre Bath.

The home side picked up a losing bonus point but at least one route into next season's Heineken Cup has been firmly closed off.

Just as disappointing against a Bristol second string last weekend, they experimented with former England full-back Matt Perry at fly-half but failed to find any rhythm until it was too late.

Nick Walshe opened the scoring from close range after five minutes but missed a 40-metre effort shortly afterwards when he might have been allowed to play advantage.

Instead the Ospreys set up camp on Bath's line and Shaun Connor's flighted past put Jonny Vaughton over in the corner for an unconverted try after 18 minutes.

Walshe replied with another penalty but the Ospreys hit back immediately as centre James Hook took advantage of indecision in the Bath ranks from Jason Spice's box kick. Connor's conversion was good and the fly-half opened up an 18-6 lead by the half hour with a drop goal and penalty.

Spice was yellow carded on 33 minutes however and Walshe kicked his third penalty to reduce the margin to three points at the break.

Ian Evans became the second Ospreys player to be sent to the sin-bin after ignoring a warning to his side for persistent infringement. Walshe landed a penalty and Bath went all out in attack against 14 men.

But they were caught cold by Stefan Terblanche's spectacular 80metre break-away try after 53 minutes which was converted by Connor.

Bath looked dead and buried at 25-12 but two tries in two minutes on the hour by centre Tom Cheeseman breathed life into Bath as they clawed their way back to 25-24.

But Connor's second drop goal after 75 minutes and another by Hook five minutes from time killed off the revival.