Aberdeen 3-0 St Johnstone

Adam Rooney scored a hat-trick for Aberdeen as they continued their undefeated start to the Scottish Premiership season with a comfortable 3-0 win over St Johnstone.Rooney headed home two of his goals, the first at the near post from a Stevie May cross and the second from close range after Anthony O'Connor had flicked on another May cross. His third came from the penalty spot with nine minutes to go.Rooney was one of two changes to the Dons' starting XI, the other seeing Greg Stewart start, with last week's goal hero Andrew Considine and midfielder Greg Tansey those dropping out.Despite the changes, the home side were fluent in their play throughout the first half, in stark contrast to their performances in the double-header with Motherwell.Indeed, the opener, after just seven minutes, came from a quickly taken free-kick. Former St Johnstone man May crossed from the left, and Rooney got in front of his man to send a diving header past Alan Mannus in the Saints goal.The goalkeeper was nearly embarrassed by a deflected Graeme Shinnie shot after 14 minutes, the ricochet wrong-footing the goalkeeper, but also taking ball the power out of the effort which allowed the keeper to recover and hold the ball just in front of the line.But the home side would not have to wait long before doubling their advantage. This time it was a corner on the right, taken short by Ryan Christie to May. His cross was headed across goal by O'Connor, and Rooney popped up at the back post to head home from just a couple of yards.Tommy Wright's St Johnstone are usually tough opposition for Aberdeen but they were hugely disappointing throughout the first half and could have gone in three goals down, had Christie made more of a swift break just a minute before the interval.It was no surprise, then, that Wright made a double substitution at the break, Paul Paton and Scott Tanser making way for Chris Millar and David Wotherspoon.Referee John Beaton had invoked the anger of the home support more than once in the first half and he did so again six minutes into the second when a clever drawback saw May burst into the area and take a tumble under pressure.His appeals were waved away but they were given a spot-kick with 10 minutes to go as Saints captain Steven Anderson sent Christie tumbling.With a hat-trick at stake there was no doubt Rooney would step up and he confidently sent Mannus the wrong way to seal the win.There could have been a fourth goal but substitute Frank Ross was unfortunate to see his effort come back off the upright just seconds after replacing Christie.