The first of three races at the Portuguese venue ran to just 14 laps and started more than an hour later than scheduled following a heavy crash for WSP300 rider Victor Steeman. The Dutch rider was taken to the hospital after being diagnosed with polytrauma and head injuries, with the incident impacting the entire day's schedule.
When the action did get underway in the flagship WSBK category, polesitter Jonathan Rea held on to the lead from pole position, with Alex Lowes moving up to second ahead of Razgatlioglu to establish an early Kawasaki 1-2.
However, Lowes’ place near the front of the pack proved to be short-lived as he soon tumbled to fifth, leaving Razgatlioglu free to chase after Rea for victory.
It took the Turkish rider until lap 6 to make the race-winning pass, the 25-year-old sending his Yamaha down the inside of Rea in a brilliant move at Turn 1.
From there on, Razgatlioglu had a relatively easy run to the chequered flag as he chalked up his ninth win of the season and first since the Magny-Cours round in early September.
Second position eventually went to championship leader Alvaro Bautista, who was able to guide his Ducati past the satellite Motocorsa Racing Panigale V4 R of Axel Bassani after a slow start and then make the pass on Rea for second with three laps to go
Rea had to settle for third after starting from pole position, extending his winless streak to 16 races stretching all the way back to the Estoril round in May.
Bassani was fourth at the finish after fighting for a spot on the podium early in the race, but he did beat the factory Kawasaki of Lowes as he continued his recent run of strong results.
Andrea Locatelli was sixth on the works Yamaha, ahead of Ducati’s Michael Ruben Rinaldi and the top Honda of Xavi Vierge.
Bonovo BMW rider Loris Baz wasn’t able to capitalise on a strong qualifying result as he slipped to ninth at the finish, ahead of GRT Yamaha’s Garrett Gerloff.
Scott Redding was running inside the top 10 until he crashed on the final lap, leaving him 18th in the final classification - four places behind the other works BMW of Michael van der Mark.
Portimao WSBK - Race 1 results:
|7||21||Michael Ruben Rinaldi||Ducati||14||12.614|
|14||60||Michael van der Mark||BMW||14||25.808|
|View full results|