Jonathan Rea suffered a huge crash at Portimao as Toprak Razgatlioglu extended his Championship lead to 45 points.
The top three contenders battled it out over the 20-lap race, with Rea, Scott Redding and Razgatlioglu inseparable.
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Rea and Razgatlioglu made contact in a thrilling opening two laps, with Redding taking the lead.
And as Rea moved for the lead on Redding, he lost control at Turn 15 with the following spectacular crash forcing the six-time champion out of the race.
With Rea gone, Razgatlioglu took from the lead from Redding at the start of lap 11, with the Turkish rider holding on for en emphatic and crucial win. Redding finished second with Loris Baz in third.
Rea will be assessed on Sunday morning ahead of the WorldSBK Warm-Up session, having already been diagnosed with multiple contusions and a left elbow abrasion.
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