Yamaha’s Razgatlioglu passed the Ducati of Redding at the penultimate corner on the final lap at the Czech venue to score his fourth win of the season by a margin of just 0.040 seconds.
With Rea not scoring, it means Razgatlioglu has closed to within 12 points at the head of the standings.
It was Razgatlioglu that led the early stages after jumping poleman Rea from second on the grid, but the Turkish rider’s stint out front was short-lived as Redding passed Rea to move up to second on the second lap before forcing his way by Razgatlioglu at Turn 1 next time by.
From there, Redding was able to stretch a lead of 1.7s as title protagonists Rea and Razgatlioglu squabbled over second.
Razgatlioglu and Rea settled into second and third respectively and were starting to close in on Redding when Rea suffered a low-side crash going into Turn 1 on lap 14 of 22.
The reigning champion remounted his Kawasaki in 11th place and was on course to salvage at least five points until he crashed for a second time at the penultimate corner on lap 18.
By this time, Razgatlioglu had closed in on Redding and on lap 19 the Yamaha man forced his way by at Turn 14.
But Redding was able to quickly regain the advantage by repassing into Turn 1 the following tour and was looking good for his first WSBK win since May’s Estoril round until the decisive final lap.
Razgatlioglu came from a long way back and forced his way up the inside into the first of the two right-handers that finish the lap, sitting up Redding to steal the inside line and subsequently victory.
Andrea Locatelli followed up his first-ever WSBK podium at Assen with another top-three finish, albeit nearly 14s down on Yamaha teammate Razgatlioglu.
Michael Ruben Rinaldi was fourth on the second works Ducati, followed by Axel Bassani, who scored his best-ever WSBK finish aboard his Motocorsa Ducati in fifth place.
Garrett Gerloff was sixth on the GRT Yamaha after a poor first lap dropped him to 10th, ahead of Honda riders Alvaro Bautista and Leon Haslam, BMW’s Tom Sykes and wildcard Marvin Fritz on the best of the FIM Endurance World Championship-spec YART Yamahas.
Rea’s Kawasaki teammate Alex Lowes fell at Turn 1 but remounted to finish 13th of 14 finishers in an attrition-heavy race, with Chaz Davies (Go Eleven Ducati) and Michael van der Mark (BMW) among the other crashers.