Aberdeen booked their place in the fourth round of the Scottish Cup with a rare away victory against St Johnstone.

A brilliantly-crafted goal from former Manchester United youngster Ben Thornley and a late second from Darren Young gave the Dons their first win on their travels since a 4-1 victory over Dundee back on October 1.

Both sides poured men forward throughout a typically frenetic cup tie but, in the end, the Pittodrie men were well worth their place in the fourth round.

Aberdeen boss Ebbe Skovdahl was forced to press young Ryan Esson into action in goal in place of the injured Peter Kjaer, but there was surprisingly no place for comeback man Russell Anderson who lost out to the returning Kevin McNaughton.

The changes did not appear to affect the visitors, who enjoyed the lion's share of the possession in the opening stages but it was Saints who threatened with the first real attack of the game.

With the Dons attacking at every opportunity, the home side had keeper Alan Miller to thank for maintaining the early stalemate in the eighth minute when he dived to turn Robbie Winters' free-kick round the post.

The game came to life on the 20-minute mark as Ryan Esson was forced to scramble across goal to hold a Paul Hartley drive and, as play raged to the other end, Stuart McCluskey did well to thwart Dadi with a last-gasp tackle 12 yards out.

And it was the Perth men who came closest to breaking the stalemate on the half-hour mark as only the woodwork saved Aberdeen.

Paul Hartley's wicked swerving corner was perfect for Stuart McCluskey but his header crashed back off the bar to Connolly who could not direct the rebound on target.

Three minutes later, Dadi was denied by a magnificent diving block by Darren Dods and 10 minutes from the break the Dons came even closer to making the breakthrough.

Derek Young and Winters combined on the left with Dadi to set up the Frenchman only six yards from goal but his netbound effort was desperately cleared off the line by Ross Forsyth.

The second half began where the first had left off with both sides sending men forward at every opportunity but failing to carve out any real chances.

Derek Young injected some pace into the Dons attack when he embarked on a mazy run which took him half the length of the pitch before playing in Winters.

However, the former Dundee United man casually lifted his shot over the bar with both Dadi and Guntveit screaming for a cut-back.

Dons boss Ebbe Skovdahl then made a crucial change with 55 minutes on the clock, which brought about the breakthrough.

Thornley, on in place of Roberto Bisconti, sneaked in behind Hartley to receive McAllister's precision pass and he produced a wonderful curling shot into the top corner from the corner of the area.

Saints substitute Craig Russell almost had as big an impact as Thornley when he found his way into the Aberdeen box in the 72nd minute but McGuire got back to block his left-foot effort.

Five minutes later the striker, who has suffered an horrendous time with injuries, fired in a long-range drive which Esson did well to palm away.

However, the Dons, who had the ball in the net through Winters only to be denied by the linesman's raised flag, eventually killed off the home side deep into injury time.

Dadi's deep cross after neat work from Thornley perfectly picked out Darren Young at the back post and he steered a volley past Miller from close range.

Teams

St Johnstone: Miller, Murray, Dods, McCluskey, Forsyth, Hartley, Kane (McBride 82), Dasovic, Djebaili (Russell 67), Connolly (Falconer 87), Macdonald.

Subs Not Used: Cuthbert, McClune.

Booked: Dods, McBride.

Aberdeen: Esson, McAllister, McGuire, Whyte, McNaughton, Guntveit, Bisconti (Thornley 57), Darren Young, Winters (Anderson 88), Dadi, Derek Young.

Subs Not Used: Preece, Clark, Tiernan.

Booked: Whyte, Dadi, Darren Young.

Goals: Thornley 58, Darren Young 90.

Att: 4,070

Ref: Kenny Clarke (Scotland).