Reigning Supercars champion Shane van Gisbergen came out on top in a frantic end to Friday practice at the Perth SuperSprint.
Times tumbled rapidly in the final moments of the 45 minute session, which ended with Van Gisbergen and Fabian Coulthard both under the previous practice benchmark.
Scott McLaughlin sat atop the order with five minutes remaining but was bumped back to 12th in the final flurry.
Jamie Whincup was the first to eclipse McLaughlin before Coulthard and finally Van Gisbergen took the top spot.
Van Gisbergen's time of 54.78s, eclipsing Whincup's previous practice benchmark from 2011 by 0.21s.
"I call him a gypsy," quipped Van Gisbergen of his engineer Grant McPherson post-session.
"He gives me no tyres all day and we put some good ones on and we're flying.
"That's the name of our game, we're always limited on tyres.
"Feeling it out all day and the cars felt terrible but we kept working hard and chipping away and bolt a new set on and find two seconds amazingly.
"The car feels good and hopefully we can keep it up tomorrow."
Coulthard added that he was happy with his day’s work, despite being pipped at the chequered flag.
“We’re sticking to the plan, doing lots of laps and lots of running,” he said.
“We’ve got a little bit more to go but we’re making progress.”
Whincup ended up third, having narrowly avoided the sand trap earlier in the session when he out-braked himself at Turn 1.
Mark Winterbottom wound up fourth ahead of Chaz Mostert and Craig Lowndes, who had an unsual spin at Turn 6.
Cameron Waters made it three Prodrive Fords in the top seven ahead of Will Davison, Todd Kelly and Nick Percat.
Alex Rullo caused the only red flag. The 16-year-old battled on track with Whincup for several laps before out-braking himself at the final corner and ending in the sand.
Lucas Dumbrell Motorsport team-mate Matthew Brabham rounded out the field, two places and 1.5s adrift of Rullo.