RAGING Gregor Townsend today warned his Glasgow side there can be no repeat of the disastrous 31-3 thumping they suffered at the hands of Munster.

Warriors host French cracks Castres, on Friday night at Scotstoun in a Heineken Cup tie that is a must win affair if their European hopes are not to be ended before Christmas.

But with Saturday's Thomond Park thrashing being Glasgow's heaviest defeat of the season– and also seeing Warriors drop out of the PRO12 play-off placings for the first time since the opening fortnight of this campaign – Townsend has warned his men that a massive improvement is a must.

The Warriors head coach said: "I was very angry and very disappointed with our performance on Saturday.

"Without doubt, it was our worst performance of the season since I have taken over and the boys know that there can be no repeat.

"I have challenged them to show that this was a blip and the only way to do that is by beating Castres on Friday night.

"That was our poorest performance of the season by a distance. We dropped off tackles and we stepped off Munster.

"We said before we came to Ireland that we had to make sure we put pressure on them but we did the opposite.

"So it is vital that we make sure we use this as motivation to get back to a far higher level of performance and show that we're the kind of side who belongs alongside the best teams in the competition."

A minor plus for Townsend was that Duncan Weir returned to the fray and it was from his boot that Glasgow earned their three points.

While Moray Low had to call off before kick-off with a bug, Glasgow came through their harrowing defeat at the hands of the Munster men without any further injuries.

Friday night's visit of Castres is the first leg of a home and away double-header that Warriors must take full points from if they are to resurrect their Pool Four hopes.

But with Saturday's defeat representing the first time Glasgow have suffered back-to-back setbacks since the opening two games of the season, Townsend is facing a major challenge to galvanise his men.

He added: "We know exactly what we have to do against Castres and it is a huge plus that the first game of the two is at Scotstoun.

"I am sure that with a big home crowd behind us we can get the win we need that will set us up nicely for the return leg in France on December 15.

"The boys know that they let themselves down at Thomond and they must show character to bounce back from that."

"So we need to make sure we have a focused and solid week in training and that we do everything we can to make sure that on Friday night we are in the best possible shape. We need to produce a performance."