The Pramac Ducati rider completed his second sprint/grand prix double in three rounds at Motegi last weekend to cut Francesco Bagnaia's championship lead down to three points.
Martin, who also qualified on pole, recovered from an early mistake after emerging from pitlane on his wet bike as the rain intensified as the leading stopper to win by 1.4s when the grand prix was red-flagged on lap 13 of 24.
