Spain’s Alvaro Bautista claimed the runner-up spot on the Aruba.it Ducati and leads the standings by 31 points from Rea at the half-way point of the championship, although Razgatlioglu has made significant inroads and is now only seven points further back in third.
The Pata Yamaha rider clinched a treble at the previous round at Donington Park and has now won six of the last eight races, with Razgatlioglu also coming out on top to win Sunday’s Superpole race from Rea and Bautista.
Razgatlioglu made a flying start to lead the race from Bautista and Michael Ruben Rinaldi (Aruba.it Ducati), but Rea fluffed his lines and was down in fifth place on the first lap.
Rea fought his way through into third past Rinaldi, who later crashed out at Turn 1 on the brakes after briefly re-passing Rea for third.
Bautista was in hot pursuit of Razgatlioglu and drafted past on the straight to hit the front, but he went straight on at Turn 1 and had to re-join the race in third behind Rea.
A determined Rea made his move for the lead with a pass on Razgatlioglu into Turn 1, while Bautista had now regrouped and was setting his sights on closing in on the leading duo.
With 12 laps to go, Bautista moved into second place behind Rea and then hit the front two laps later.
It seemed as though the Ducati rider would have the pace to pull away, but Razgatlioglu was on a charge on his Yamaha.
The Turkish rider picked off Rea and then edged ahead of Bautista at the penultimate corner with seven laps remaining.
Razgatlioglu then gradually opened a gap over Bautista and Rea, who were unable to respond.
The top three remained unchanged on the final six laps as Razgatlioglu went on to clinch victory by 0.756s from Bautista, with Rea two seconds further back in third. It was Razgatlioglu's 24th victory in World Superbikes and Yamaha's 101st in the series.
Scott Redding finished in fourth for BMW Motorrad ahead of Axel Bassani (Motocorsa Ducati), while the top six was completed by Andrea Locatelli (Pata Yamaha).
Eugene Laverty did not start the race after suffering an issue with his forearm, while Rea’s team-mate Alex Lowes was ruled out of the race through illness.
The championship now enters a long summer break, resuming again with round seven at Magny-Cours in France from September 9-11.
Rea and Lowes will now travel to Japan to take part in next weekend’s Suzuka 8-Hours race for Kawasaki.