Click here for full BSB FP3 results from Cadwell Park
Josh Brookes has taken a clean sweep of the free practice sessions at Cadwell Park despite a small crash in the closing stages.
The Milwaukee Yamaha rider claimed top spot in FP3 with a 1m 26.966s but was made to sweat after suffering a small off at the chicane section of the Lincolnshire circuit with two minutes left in the session.
However, none of his rivals were able to beat the Australian's time which means he heads into qualifying after topping every session.
The final free practice was briefly suspended by a red flag with a little over seven minutes remaining after Dan Linfoot's Honda CBR1000RR expired down the start-finish straight and spilled oil on the track. After a lengthy period to clean up the circuit the session was restarted which provided a quick qualifying-style blast to the chequered flag.
As the riders got up to speed Brookes suffered his off at the chicane but recovered his Yamaha R1 to rejoin the action with two minutes remaining. Billy McConnell and Peter Hickman also had crashes at the chicane and Chris curves respectively while pushing for outright single lap pace.
In the opening stages Be Wiser Kawasaki's Buchan headed proceedings with his fastest lap of the weekend a 1m 26.981s, albeit just under four-tenths off Brookes' fastest lap from Friday.
Buchan held on to second to secure a hat-trick of P2 places during the free practice sessions and only lost out to Brookes by a narrow 0.015s. 2014 BSB race winner Tommy Bridewell made encouraging gains to take third spot at the end of the sessions in front of Luke Mossey, McConnell and new Buildbase BMW rider Richard Cooper.
Bennetts Suzuki's Christian Iddon, who grabbed third at the end of Friday practice, took seventh place ahead of 2011 BSB runner-up John Hopkins while Martin Jessopp and Hickman rounded out the top ten.
Further back Shane Byrne continued to struggled with the PBM Kawasaki, ending the session 12th just behind James Westmoreland, while there was more misery for three-time BSB champion Ryuichi Kiyonari who crashed unhurt at Park corner having completed just four laps on his Buildbase BMW, ending the session in 16th.