The Tech 3 rider had spent the majority of the session on the fringes of the top three as fellow Yamaha man Jorge Lorenzo led the way with a time of 1:56.322, which remained quickest until the final few minutes.
Having endured a couple of unwanted slides, Crutchlow opted to run with a harder front tyre for the final half of the session and went on to post the quickest overall time of 1:56.156 shortly before the chequered flag fell.
The session was a fairly muted affair, with little change in the order as Lorenzo's time was good enough for second quickest while current championship leader Marc Marquez made improvements on Friday to go third fastest.
Valentino Rossi was fourth quickest, ahead of Dani Pedrosa and Alvaro Bautista.
Friday pacesetter Stefan Bradl could not repeat his form from yesterday and was eighth quickest.
Andrea Iannone suffered the ignominy of being the only rider to crash out in the session. He low-slided while following Rossi into Turn 5 as he tried to post the 10th fastest time.