Chaz Davies started on pole on Saturday with Rea in second and Bautista third.
Despite having admitted last month that he suspected there were no tracks on which he could beat Bautista, who won the first 11 races of the season, Kawasaki rider Rea took the lead on the first lap, while there was disappointment for Davies who had to drop out in the same lap due to a problem with his bike - his second withdrawal of the year.

'Finally, finally, finally!' - Rea wins first race of the season

Toprak Razgatlioglu: I'm really happy, it's my best race
23/06/2019 AT 13:11
Having dominated last season with 17 victories out of 26 - ultimately winning the world title, as he had the three seasons prior - Rea has struggled to keep up with Bautista this year.
Ironically, Bautista's run would come to an end just down the road from the home of his team, Ducati.
Trialling a new tyre, Rea seemed back to his previous form on Saturday, extending his early lead to almost 8 seconds with six laps to go.
Meanwhile it was Toprak Razgathoglu who came in third, having fought back from 11th on the grid, to take his third career podium finish and first of the season.
Speaking after the race, Rea said: "I needed that for my confidence, for my team...I couldn't not win, I talked myself into it. For the last three weeks in the gym I visualised winning."
He said: "I put my head down from lap one made the race mine. I hope I've found the sweet spot now and we can keep this going on tomorrow and into the season."

Rea: I put a lot of pressure on myself to win in Imola

Bautista said after the race he was happy with his choice of tyres and added: "We knew on this track I'd struggle, but I'm happy with the second place."
Bautista went into the day with a 53-point lead over Rea and ended with 256 to Rea's 208.
Rea: Toprak did an incredible job
23/06/2019 AT 12:54
The finish: Rea holds off Razgatlioglu to win at Misano
23/06/2019 AT 12:44