The Ulsterman became the most successful rider in the history of the series after joining Kawasaki in 2015 and winning six world titles in a row.
He also chalked up a record 104 victories on the ZX-10 during that time, with his last win – his only success this season – coming at Most in the Czech Republic in the summer.
On Sunday, Rea slid out of the final race of 2023 while leading by just under one second. He was able to re-join the action and eventually finished in 17th place on his Kawasaki swansong.
Spain’s Alvaro Bautista, crowned champion for the second consecutive season after he won Saturday’s opening race, completed a treble on home soil when he was declared the winner after Toprak Razgatlioglu (Pata Yamaha) – who edged out his Ducati rival in an epic showdown – was handed a one-place penalty for exceeding the track limits on the last lap.
Swiss rider Dominique Aegerter (GRT Yamaha) completed the rostrum.
Rea, third in this year’s final standings, earlier stood on the podium one final time as a Kawasaki rider after claiming third in the Superpole race behind Bautista and Aegerter.
The 36-year-old will replace Razgatlioglu in the Pata Yamaha team for 2024, with the Turkish rider moving to the Shaun Muir-run factory BMW team.
Rea, who will test the Yamaha R1 for the first time in Tuesday’s post-season test at Jerez, said: “It’s tough to put into words the Kawasaki journey I’ve been on. I just want to thank them because back in 2015 they gave me the opportunity to ride an incredible bike.
“I jumped on it and realised all my dreams. Everybody inside the team has made me feel incredible throughout all the journey – good times and bad.
“I was leading the race today and dominating the race for a certain period. Instead of just giving up that little bit to let the bike turn naturally I was just squeezing, so a small error but big consequences.
“So, frustrating not to finish in a better way but it takes nothing away from what we have achieved together,” Rea added.
“Of course, it’s a tough day for everyone doing our goodbye and whilst I’m really excited for what’s next, I really wish the team all the best in their future as well because they’re more than a team – they’re my racing family.
“I’ve spent so much time with them travelling from race to race and you become friends, so that’s what makes it a little bit harder.”
On his upcoming new challenge as a Yamaha rider after nine years on Kawasaki machinery, Rea said the deal had relit his fire as he sets his sights on a seventh world title.
“I really respect Kawasaki and the lengths they went to to try and push things forward, to keep me motivated and happy, but I’ve been here nine years – it’s not normal in racing to be nine years in one team – and I could only liken it to someone like Marc Marquez, and we know what’s happened there,” he said, referring to Marquez’s decision to leave Honda for a satellite Ducati ride with Gresini Racing next year.
“So, for me it’s a new motivation, something new and it lit my fire, and my family supported it. Who knows – I move a few doors down tomorrow and I’m sure I’ll face my own challenges there, but it’s going to be a different challenge and one that’s going to light some fire.”