Bradley Smith took the 125cc championship lead with his second win of the season at Mugello.
The Aspar Aprilia rider succeeded in escaping from his rivals and avoiding the traditional slipstreaming for the lead on the last lap.
Nico Terol pushed Smith all the way to the flag, with Julian Simon having to settle for third after losing touch with the leaders in the closing stages.
The opening laps saw a typically frenetic Mugello lead battle with seven riders drafting each other.
Smith then briefly made a break, benefiting when Andrea Iannone's bike slowed mid-corner while in second behind him on lap five. As Iannone trundled into retirement, continuing his miserable recent run, Smith was handed a one-second lead as his rivals had to jink around the Italian's bike.
But Terol and Simon managed to reel Smith back in and resume their earlier battle. It looked like a three-abreast sprint to the line was in prospect, until Simon lost pace and dropped away from Smith and Terol in the final laps.
Determined to avoid being out-dragged on the final run to the line, Smith pushed flat-out around the last lap and just pulled out enough of an advantage to stop Terol getting a tow, allowing the Briton to clinch his second win of the season and take the points lead in the process.
Pol Espargaro charged through to fourth, beating Marc Marquez, with Johann Zarco completing the top six after the best ride of his rookie season so far.
At one stage it looked like three of the top five finishers might be Britons, as Scott Redding and Danny Webb joined Smith in the battle for the lead. But Webb crashed out of fourth before half-distance, and Redding fell back to seventh after a wild slide on the last lap.
Results to follow