(Reuters) - Honda's MotoGP championship leader Marc Marquez won in Germany for the seventh year in a row, across all categories, on Sunday after a mid-race tyre gamble paid off.

The Spaniard forged 48 points clear at the top of the standings after Yamaha's reigning champion and main rival Jorge Lorenzo finished only 15th.

Britain's Cal Crutchlow, on an LCR Honda, was second and 9.8 seconds behind with Italy's Andrea Dovizioso third for Ducati. Italian great Valentino Rossi, Lorenzo's team mate, finished eighth.

At the halfway point in the season, after nine of 18 rounds, Marquez has 170 points to Lorenzo's 122. Rossi has 111.

Marquez, the 23-year-old who looks set for his third MotoGP title, had started on pole and pitted on lap 17, on a drying track after heavy rain just before the start, following an excursion into the gravel trap that dropped him to ninth.

The Spaniard was the first of the leading riders to change bikes but the move paid off with Marquez charging back through the field at the twisty Sachsenring circuit near Chemnitz in eastern Germany.

"At a certain point today, I thought my run at this circuit was going to come to an end," said Marquez, whose lap times on slicks were four seconds faster than those still on wets.

"But in the end we succeeded and earned a very good result, especially considering how Valentino and Jorge finished the race.

"It's always very difficult to decide when to change bikes, and perhaps we made our switch very early...but I decided to take a chance and it went well," he added.

Lorenzo, who struggled all weekend, said it had been clear after the warmup that he would not be fighting with the other frontrunners.

"At least I was better and faster than during the warm up," added the Spaniard.

"When the track started to dry I was losing positions because I didn't‘t feel safe or have confidence in the front tyre, either on braking or in the corners."

German rider Stefan Bradl, on an Aprilia, missed the race after crashing in the warm up and being taken to hospital for a CT scan after suffering concussion.

Malaysia’s Khairul Idham Pawi, who became his country's first grand prix winner in Argentina in April, took his second career victory in the Moto3 category for Honda Team Asia.

The next race is in Austria on Aug.14.

(Reporting by Alan Baldwin, editing by Toby Davis)