Loris Capirossi's final race appearance on home Italian asphalt ended in disappointment when the Pramac Ducati rider retired on lap nine.
38-year-old Capirossi, who will retire at the end of this season, pulled into the pits with chain and sprocket problems soon after the start.
Although he later returned, the gap to the others was so big that the #65 - who had qualified 16th - elected to retire.
"We managed to do something good during the warm-up [11th], but the race was really a disaster," said Capirossi. "I had a problem with the clutch on the start, and then another one with the chain as a result.
"I came back to the garage to try to fix the situation, but it was useless because the gap to the others had become huge in the meantime."