Jonathan Rea triumphed in a hard battle with Chaz Davies to equal the all-time World Superbike win record belonging to Carl Fogarty after taking his 59th victory in race two at Imola.
Michael Ruben Rinaldi took the holeshot on the run down onto Tamburello ahead of Ducati stablemate and poleman Davies, while Rea carved past Kawasaki teammate Tom Sykes and Aprilia's Lorenzo Savadori into the Variante Alta to take sixth.
Rea continued his charge from ninth on the grid by taking fifth away from Marco Melandri at the Variante Alta on the following lap, and moved ahead of Yamaha's Michael van der Mark on lap three for fourth.
Davies carved past Rinaldi into the final chicane at the end of the third tour, with Rea moving ahead of Xavi Fores and Rinaldi in quick succession on lap four to begin his assault on the lead.
Rea shadowed Davies for the next 10 laps, with the Northern Irishman making his first attempt at taking the lead on lap 11 at Tamburello.
Davies repelled the Kawasaki rider, and struck back hard once again at the Tosa hairpin on the following lap when Rea launched a daring raid for the lead.
Rea eventually made a move stick into the Variante Alta on lap 14 and immediately built up an advantage of well over a second, which he continued to extend over the remaining laps.
Four seconds clear of Davies on the final lap, Rea eased to his fifth win of the year and a new record of 17 career double victories, while also opening up his championship lead to 47 points over second-placed Davies.
Teammate Sykes got the better of Fores in the closing stages to claim third, while Jordi Torres trailed the Barni rider home to complete the top five.
Alex Lowes held off Rinaldi in the closings stages for sixth, while Toprak Razgatlioglu, Eugene Laverty and Leandro Mercado rounded out the top 10.
Razgatlioglu's teammate Leon Haslam had been set for points, but a crash on the penultimate lap ended his hopes, and the British Superbike wildcard crossed the line in 16th.
Van der Mark and Melandri also failed to make the finish, after the Yamaha rider collided with Melandri at Rivazza on lap nine while the pair were debating fifth.
The incident has been placed under investigation. Lorenzo Savadori, wildcard Vladimir Leonov and Honda's Jake Gagne joined van der Mark and Melandri on the sidelines.
|5||81||Jordi Torres||MV Agusta||15.479|
|7||21||Michael Ruben Rinaldi||Ducati||17.197|
|Ret||33||Marco Melandri||Ducati||11 laps|
|Ret||60||Michael van der Mark||Yamaha||11 laps|
|Ret||5||Vladimir Leonov||Kawasaki||13 laps|
|Ret||32||Lorenzo Savadori||Aprilia||15 laps|
|Ret||45||Jake Gagne||Honda||15 laps|