Harlequins boss Conor O'Shea admits his side are only too aware of the threat posed by Northampton Saints on Saturday.
Quins will head to Franklin's Gardens after an impressive start of the season - with the defending champions currently top of the Premiership standings and having won four out of four of their Heineken Cup games.
However, the Saints are once again in the mix having only just missed out on the Premiership final last season when Harlequins overturned an eight-point deficit in the final 10 minutes.
"Going to play Northampton Saints at Franklin's Gardens is as big a test as it gets," O'Shea told Sky Sports.
"Jim Mallinder and Dorian West have been doing a tremendous job there. They play with passion and intensity and play a good brand of rugby."
Northampton showed how dangerous they can be when they responded to their home loss to Ulster in the Heineken Cup by inflicting a first defeat of the season on the Irishmen at Ravenhill.
And having needed the trusted boot of Nick Evans and a late try from Joe Marler to snatch a 25-23 win in the Premiership play-off semi-finals last season, O'Shea is expecting another close game.
"Against Ulster at home, I think too many people looked just at the score line and not at the performance as there were some fine margins," said O'Shea.
"Northampton, though, reacted as you have expected at Ravenhill.
"We know from our semi-final in the Premiership play-offs what to expect. We were 10 minutes from losing, we were down and out but somehow we managed to get the result.
"I am sure it will be another keenly-contested game."
Conor O'Shea was promoting the QBE Coaching Club; an initiative run between QBE and the RFU to recruit and train 2,015 new level two rugby coaches by 2015. For more information please visit www.QBErugby.com
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