Last updated on .From the section Scottish Premiership

Aberdeen secured a second 3-0 win over St Johnstone this season, with Adam Rooney, Kari Arnason and Ryan Christie on target in Perth.

Rooney slammed home the opener from 14 yards after exchanging passes with Greg Stewart.

Former Saint Stevie May rattled the crossbar shortly before Arnason's close-range header found the net.

Christie's second-half free kick took a deflection off the defensive wall on its way past goalkeeper Zander Clark.

Aberdeen, who remain third, knew that a win could have taken them up to second spot in the table, but it was St Johnstone who created the first opportunity of the evening.

Stefan Scougall collected a ball from Murray Davidson and moved at pace down the right wing. His ball into the box was met by Davidson, who had continued his run forward. His first effort was blocked with the rebound going just wide of goal.

Adam Rooney scored a hat-trick when the two sides met in September

Aberdeen though, began to ease their way into the game as captain Graeme Shinnie ploughed his way forward from the left-back position and his effort from the edge of the box deflected wide of the target.

The opening goal came after a wonderful flowing move from the visitors. Shinnie and Stewart combined before the latter played in Rooney, who showed all of his predator instincts to hammer the ball home.

The creativity of Stewart along with Christie and Kenny McLean was beginning to have a major impact on the game as they took control of the midfield area.

May then struck the woodwork from inside the box after a graceful pass by Christie.

Saints boss Tommy Wright was forced into a change when Davidson came off second best after a challenge with McLean and, just after the half-hour mark, Aberdeen doubled their advantage.

May floated in a corner from the left and, after it glanced off a couple of players, Arnason jumped highest at the back post to head in number two for the Dons.

22-year-old Ryan Christie scored six league goals for Aberdeen last season

St Johnstone came close to reducing the deficit twice before the break only to be denied by Joe Lewis.

It was Steven MacLean who was first to have a go. Inside the six yard box, the Saints striker looked all set to score before Lewis made the block. Then Michael O'Halloran tried his luck from 22 yards and this time Lewis was at full stretch to save.

Aberdeen continued to push forward in the second-half with Rooney blasting over from close range when he really should have found the target.

However, the 1,045 Aberdeen fans inside McDiarmid Park did not have to wait too long for their side's third.

Christie's free-kick from 22 yards out took a deflection off the wall that wrong footed Clark in the Saints goal, with the ball ending up in the back of the net.

Aberdeen had the luxury of replacing Stewart, Rooney and May, but there was to be no let up in the visitors' search for goals, with substitute Gary Mackay-Steven coming close with an effort from 10 yards that drifted just wide.

Despite their efforts, the Dons had to settle for three goals as St Johnstone's run of home games without a win that stretches back to 23 September continues.

St Johnstone manager Tommy Wright: "It's same old, same old. I'm like a broken record. We've got to do better.

"We've just had a good chat in there about it. It's almost as if we've lost a wee bit of what we're about.

"I know managers at big clubs used to say to me that they used to hate coming here and used to hate playing against us.

"You could argue that you maybe want to be playing against us this season."

Aberdeen manager Derek McInnes: "I think if we said prior to the game we would get another clean sheet and another three points we would have taken that, but to score three goals and have created numerous chances at a place like St Johnstone, we've got to be pleased with our work.

"All of sudden, we've got good confidence about our performance.

"I thought it was a very professional performance.

"I thought we were in charge for a lot of the game and it's not always the case here."