Kerr heads in corner after Murphy & Irvine hit bar for Hibs
Rooney bullets in from free-kick & Conway adds third
Winners will play St Mirren or Livingston in the final on 28 February
FT: Aberdeen 2-0 Motherwell
Aberdeen manager Derek McInnes tells BBC Scotland: "I thought we were good throughout. We looked far more robust with our defending. The biggest drain on any team is losing cheap goals so the clean sheet was important for us today.
"I'm a bit disappointed we haven't scored more than two, but I would have taken that before the game."
St Johnstone 1-0 Hibernian
Look up sucker-punch in the dictionary and no doubt you'll see a description of Jason Kerr's header.
His effort separates the two sides at the break. Incredible stuff.
Image source, SNSJason Kerr celebrates after nodding St Johnstone in front
Penny for your thoughts? Hibs peppered the St Johnstone goal but have nothing to show for the fruits of their labours.
Enter Jason Kerr to show them how it's done, his bullet header giving St Johnstone a surprise, eye-popping lead.
Zander Clark has been in inspirational form in goal for St Johnstone; Hibs have also hit the woodwork twice.
St Johnstone are 45 minutes away from the League Cup final, unless Hibs find their shooting boots and a ruthlessness in front of goal.
St Johnstone 1-0 Hibernian
John Collins
Former Hibs manager on Sportsound
Quote MessageIf I was [Hibernian manager] Jack Ross right now I'd want Jamie Murphy wide left combining with Josh Doig. They've combined twice and got good balls into the box.
St Johnstone 1-0 Hibernian
St Johnstone keeper Zander Clark has been equal to the task in the face of a tidal wave of Hibernian attacks.
If Clark has been beaten, then the woodwork has come to Saints' rescue.
Jason Kerr's bullet header has given St Johnstone an unlikely lead - but Clark's heroics to stem the Hibs' tide have proved crucial.
Image source, SNSZander Clark has denied Hibernian time and again
St Johnstone 1-0 Hibernian
Richard Foster
Partick Thistle defender on BBC Radio Scotland
Quote MessageRyan Porteous gets caught under the ball, he doesn't have the same aggression as Jason Kerr, and it's a great header
Jason Kerr
This is why we love football. Talk about a goal against the run of play. St Johnstone have been penned in for long spells but they break the deadlock with a goal of stunning simplicity.
Jason Kerr rises highest in the box to bullet a header home from a corner, beyond the despairing grasp of the helpless Ofir Marciano.
Game. On.
Image source, BBC SportSt Johnstone 0-0 Hibernian
Jackson Irvine goes agonisingly close to breaking the deadlock. This time his header from Paul Hanlon's cross clips the bar and out for a goal kick.
With St Johnstone showing more attacking intent, Hibs are hitting them on the counter and getting closer and closer to the opening goal.
St Johnstone 0-0 Hibernian
Hibs continue to knock on the door. Martin Boyle whips in a menacing cross... Jackson Irvine twists his body before guiding a header narrowly wide of goal.
St Johnstone proving to have more lives than a Perthshire cat.
St Johnstone 0-0 Hibernian
Hibs have yet to score but are proving the more impressive of the two sides. Had it not been from Zander Clark's Zumba class-style heroics in goal - and the woodwork denying Jamie Murphy - then the Edinburgh side would have their noses in front.
St Johnstone 0-0 Hibernian
John Collins
Former Hibs manager on Sportsound
Quote MessageMurphy's got to bury that. Good save to start with, good football from Hibs, but he'll be disappointed he's not burst the net with that.
St Johnstone 0-0 Hibernian
What a save! In fact, make that a double save! Martin Boyle's corner kick is flicked on and then directed towards goal by Paul Hanlon. But Zander Clark, flying through the air like Superman, claws the ball away.
Jamie Murphy then sees his second effort come back off the woodwork after being denied by Clark.
St Johnstone somehow survive and it remains goalless.
St Johnstone 0-0 Hibernian
Plenty in the way of endeavour but little in the way of goalmouth action so far. We're awaiting our first piece of skill or creativity to spark this semi-final into life.
Image source, SNSChris Kane and Alex Gogic vie for possession
St Johnstone 0-0 Hibernian
Jack Ross' side appear to be growing in confidence but have yet to turn their possession into tangible efforts on goal.
It remains goalless as we approach the 15-minute mark.
St Johnstone 0-0 Hibernian
Martin Boyle's deflected effort sails wide of Zander Clark's goal for a corner kick for Hibernian.
However, the Edinburgh side fail to force the St Johnstone keeper into a save from the set piece.
St Johnstone 0-0 Hibernian
John Collins
Former Hibs manager on Sportsound
Quote MessageHibs have probably been the better team without playing great football. St Johnstone - you can see the tactics, any time the goalkeeper has it they just get the ball up the pitch. They've had no possession. They're causing Hibs no problems.
St Johnstone 0-0 Hibernian
St Johnstone come roaring forward, aiming to put pressure on the Hibs defence but captain Paul Hanlon is alive to the attack, mopping up the danger and clearing his lines.
St Johnstone 0-0 Hibernian
Richard Foster
Partick Thistle defender on BBC Radio Scotland
Quote MessageHibs are trying to pass the ball. St Johnstone have yet to settle and are going long. Hopefully the game settles down and we see some good football.
St Johnstone 0-0 Hibernian
With no supporters inside the stadium, every player shout, holler and peep of the referee's whistle stands out at Hampden.
Even the sound of the ball being booted high into the night sky in Glasgow sounds amplified.
We're all looking forward to enjoying football with capacity crowds again - fingers crossed it happens again soon, when it's safe to do so.
St Johnstone 0-0 Hibernian
Perhaps unsurprisingly, neither side has yet to settle into any kind of rhythm in the first of this weekend's semi-final ties.
Hibs force a corner... St Johnstone keeper Zander Clark comes to collect. But he spills it under the close attentions of Paul Hanlon but the keeper is reprieved by the referee Nick Walsh's whistle for a free kick.