Toprak's victory by seven thousands of a second is the joint-fifth closest finish ever witnessed at a World Superbikes Championship.
There was high drama right at the start as Rea was pegged back having made contact with Tom Sykes (BMW Motorrad WorldSBK Team), who took the first pole position in the Superpole session with a new outright lap record of 1:29.230, in lap 1.
And despite impressively charging through the pack from 18th, the five-time Superbikes champion flew off his bike with 17 laps left on turn 8 as he was going outside Italian Michael Ruben Rinaldi (Team GOELEVEN).
Jonathan Rea's race-ending crash in Race 1
With Rea out of the picture, seven riders were in the frame for first and it finished with Razgatlioglu coming out on top with Alex Lowes (Kawasaki Racing Team WorldSBK) and Scott Redding (ARUBA.IT racing – Ducati) - in his first race - taking second and third respectively to make up the second-closest podium finish ever.
After being checked at the medical centre, Rea was declared fit after suffering a right knee contusion.
REA 'FRUSTRATED' TO CRASH OUT
"So frustrated. I felt that after what happened in the first lap I thought I was making good ground," said Rea.
"I felt great with the bike. I was setting up Rinaldi, coming in for pass coming in out wide at the hayshed as he opened up and started losing the front and down I went.
"I'm relatively OK. I stayed down for a while and burnt through to my leg but frustrated to start the year like that but there's plenty of battles yet and we've got tomorrow as well.
"The sprint race is going to be flat 'til the mat for ten laps.
"The second race seemed like the pace was being controlled quite a lot. There were five guys there at the very end so I'm sure I can be that battle and be in the battle for the last lap."
TOPRAK DELIGHTED TO TAKE TOP SPOT
Toprak delighted to take Championship lead
"I'm really happy because for me its the first day with everyone," said Toprak.
"I remember two years ago the podium was not possible but I'm really happy today.
"The last lap there was too much sliding because my tyres were destroyed so tomorrow we work for safer tyres."