Honda's Marc Marquez secured his fifth consecutive victory of the season in the Australia Grand Prix after Yamaha rider Maverick Vinales crashed on the final lap in the lead. The reigning world champion had a slow start along with Vinales on the Philip Island circuit, while Yamaha's Valentino Rossi secured the lead in what was his 400th GP start. It was an interesting top order this time with Rossi followed by LCR Honda's Cal Crutchlow and Aprilia rider Andrea Iannone at P3. With Vinales crashing on the last lap, Crutchlow was promoted to P2, while Pramac Ducati's Jack Miller took the final spot on the podium.
The Australian GP started with Vinales on pole ahead of Petronas Yamaha rider Fabio Quartararo and Marquez in the front row. However, it was the fourth-placed Rossi who had a strong start and led the race early on. Quartararo seemed confident for another battle in the top order but his plans were thwarted after a crash with Ducati's Danilo Petrucci after just two corners put both riders out of contention.
Meanwhile, Rossi secured his lead which lasted for the first three laps as Crutchlow passed the rider. The Italian racer could not retain P2 and dropped positions to seventh. The racer then spent the majority of the race trying the climb up, only finish at P8 at the end of the race. At the top, Crutchlow and Iannone exchanged places for the lead but the Briton ensured to secure the top place in the new few laps. Iannone, on the other hand, faced heat from Marquez and Vinales.
Vinales, who was running fourth by Lap 10, found the opportunity to overtake Marquez and Iannone and was back in the lead passing Crutchlow on Turn 4 of the same lap. The Yamaha rider was comfortable in the top spot but Marquez soon passed Crutchlow to take P2 and was now shadowing Vinales on every turn. The nine rider freight train from the early laps of the race was now reduced to just the top two as the riders built a massive gap over the rest of the field.
Marquez followed Vinales over the next 17 laps of the race but the gap between the riders was down to less than a tenth of a second. The Honda rider was now looking for the right moment to pass Vinales and he did on the final lap as he slipstreamed the rider on the main straight and held off Vinales at Turn 4. Vinales once again attempted to pass Marquez at Turn 10, but the rider crashed as he exited the corner, allowing Marquez to take his 11th victory of the year, 11.413s clear off Crutchlow. With the win, Marquez surpasses Mick Doohan to become the most successful rider on a Honda machinery with 55 wins.
The Vinales crash pushed Miller to the podium in his home race, ahead of his Pramac teammate Francesco Bagnaia. Coming in fifth was Joan Mir of Suzuki, in what is his best result so far, while Iannone was placed sixth, having faded after a strong start. Ducati's Andrea Dovizioso finished at P7 ahead of Rossi, while the otherwise fantastic Alex Rins of Suzuki had to settle with P9, despite moving up to P4 at early in the race. Aprilia's Aleix Espargaro finished in the tenth position, ahead of Franco Morbidelli of Petronas Yamaha. KTM rider Pol Espargaro finished at P12 ahead of Johann Zarco in his debut race with LCR Honda, while Honda's Jorge Lorenzo had another forgettable race finishing 16th, behind Avintia Ducati's Karel Abraham and Tech3 rider Hafizh Syahrin.
Apart from Vinales, Petrucci and Quartararo, Tito Rabat and Mika Kallio were the other riders to take DNF in the race.
