Mitchell Johnson's career-best six wickets and Shane Watson's aggressive innings of 69 runs led Australia to a seven-wicket victory in the opening one-day international against Sri Lanka on Wednesday. Johnson's left-arm seamers claimed 6-31 to to restrict Sri Lanka to a modest 191, with lower-order batsman Suraj Randiv top-scoring with a six and four boundaries in 41 runs. Watson then hit six sixes and five boundaries to help Australia to its first win of the tour, assisted by half-centuries from captain Michael Clarke (53 not out) and former skipper Ricky Ponting (53) at Pallekele International Stadium.