World Superbikes: Jonathan Rea fifth as Marco Melandri wins series opener
Triple World Superbike champion Jonathan Rea was fifth in the first race of the 2018 season at Phillip Island, won by Italian Marco Melandri.
Rea had been lying second but dropped down the field after suffering tyre issues late in the race.
The Northern Irishman is chasing a record-equalling fourth title and will hope for better in Sunday's race two.
England's Tom Sykes, who led for much of the race, finished second, with Chaz Davies, from Wales, third.
Early pacesetter Sykes led Kawasaki team-mate Rea but Ducati-mounted Melandri overtook both riders to secure an impressive victory at the opening round in Australia.
The former MotoGP rider's margin of victory was 1.18 seconds, with Davies more than eight seconds behind Sykes in third.
Spaniard Xavi Fores was fourth on another Ducati, with Alex Lowes sixth, Leon Camier seventh and Eugene Laverty eighth on his Aprilia.
Another championship success would see Rea, 31, equal Carl Fogarty's record tally of titles - although the Englishman's series successes did not all come in consecutive seasons.
The Isle of Man-based rider had won five of the last six races held at Phillip Island, and with his total of wins in the series standing at 54, he remains five short of Fogarty's all-time benchmark.
Rea enjoyed double triumphs at Phillip Island in 2016 and 2017, having taken a win and a second place in his first year as part of the Kawasaki team in 2015.