Ospreys wing Shane Williams believes the Welsh region must learn quickly from the mistakes they made against Saracens at Wembley on Saturday ahead of the return fixture on Friday.

The Ospreys lost 31-26 to the English Champions and find themselves three points behind them in Pool 5.

Williams, whilst acknowledging there's a lot to work on believes it will be a different story when Saracens travel to the Liberty Stadium this weekend.

"It was a disappointing performance really," Williams told ERC.

"We had all the intentions of trying to come here to win the game of course, but we didn't have enough of the ball, we didn't play territory very well when we did have it and our discipline at times was really poor. It's a short turnaround now and hopefully we can learn from our mistakes this week.

"I don't know what the stats were, but Saracens had the ball more than us and we showed that when we do get the ball we can do things with it. The important thing for us next Friday is trying to get hold of the ball, and when we do, stop conceding silly penalties that give them the ball straight back. I think that was our downfall.

"We've got to learn very quickly with the short turnaround. We know a lot about them but now it's about making sure that in these six days we learn from our mistakes and up the performance.

"We've got such a good record at the Liberty Stadium but if we play like we did today that record could be shot. We've got plenty of things to improve on this week."