Italy's Andrea Dovizioso's challenge for a top three finish at Jerez faded after deteriorating grip hampered his progress in the latter stages of the race.
Unlike his Monster Yamaha Tech 3 team-mate Cal Crutchlow, Dovizioso chose a softer compound Bridgestone front tyre and experienced a loss of grip when he needed it most.
Dovi had been involved in the battle for the top three in the first 10 laps of the race, but was unable to sustain the challenge and eventually came home in a comfortable fifth position.
“It has been a very tricky weekend because I don't particularly like this track and while I am not completely comfortable with the Yamaha YZR-M1 machine it means I struggled quite a lot,” he said.
“What I need more than anything is time in the dry to improve my performance and show what I know I am capable of. I am really happy with my start today and for the first laps of the race I was able to fight in the leading group and this helped collect a lot of information that will help me improve in the future.
“It was very interesting following Cal because he is still much faster than me entering the corner and I need to adapt my style more to take profit in this area, which is the strong point of the Yamaha,” he added.
“I also made the wrong choice with the front tyre. I wanted to race with the hard one like Cal but I changed on the grid to the soft option as all the top guys selected the softer tyre.
“But from the middle of the race I couldn't maintain my pace to stay with Cal and Dani,” said Dovizioso.
“It was still a positive experience with everything I learned, so I am looking forward to hopefully a completely dry weekend in Estoril.”