Marc Marquez took his fifth race victory in a row during the German 125cc Grand Prix on a drying track at the Sachsenring, after title rival Pol Espargaro crashed out.
Morning warm-up had been held in soaking wet conditions, but the weather quickly improved, prompting lots of late tyre changes on the grid.
The front row - Marquez, Espargaro, Bradley Smith and Sandro Cortese - joined the majority of the field in swapping wets for slicks, although some lower down the order saw the chance to pull clear with wets and hope they could hang on as the track dried.
The contrast in tyre choices saw home star Jonas Folger, running full wets, charge from eleventh to first on the opening lap with fellow German Marcel Schrotter in second (also on full wets).
Smith was the top slick rider in third by the end of the first lap of 27.
The tyre tipping point came on lap four when Marquez set the fastest lap of the race on slick tyres. The Spaniard had dropped to sixth in the early laps, but he and Espargaro were now past Smith and taking chunks of time out of second-placed Schrotter.
Race leader Folger, whose advantage over the first of the slick riders (Smith) had peaked at 6.8sec at the end of lap four, was then overtaken by both Marquez and Espargaro through turn one on at the start of lap seven. The wet tyre gamble hadn't worked.
Marquez and Espargaro then disappeared up front, pulling 13sec clear of a four-way battle for the final podium position - between Randy Krummenacher, Esteve Rabat, Smith and Tomoyoshi Koyama - by the halfway point of the race.
And the Marquez/Espargaro advantage just kept growing, peaking at a colossal 24sec.
The pair exchanged the lead periodically, with Marquez enjoying a clear advantage out of the last turn and along the home straight. But what was shaping up for a last lap showdown ended early when Espargaro suffered a massive highside while leading with three laps to go.
The Tuenti Derbi rider swung sideways at high-speed after running over a kerb and touching the grass, and was lucky not to hit by Marquez as he was thrown off his bike and slid down the track.