The Aviva Premiership leaders progressed to the last four following a 27-16 over Ulster yesterday.
The coach told Sky Sports News: "They were probably the best team we had played all season.
"For us to be 27-9 up with five minutes to go says a lot about the quality of our performance. We've worked unbelievably hard, especially defensively, where we were brilliant throughout the match.
"The players have an unbelievable work ethic for each other. We defended really well, we were good at the breakdown and forced them to play most of the game from their own half, and when we got into their 22 we generally came away with something."
Saracens will face the winner of this afternoon's match between Toulon and Leicester Tigers in the semi-finals.