Celtic hit four goals in 12 first-half minutes to sweep past St Johnstone and into the Scottish Gas Scottish Cup final.

The holders wreaked vengeance following defeat in Perth two weeks ago as they won 5-0 to set up a return trip to Hampden to face Aberdeen on May 24.

With Celtic needing just one point from their last five matches to wrap up the William Hill Premiership title, the final is set to give Celtic the chance to seal the first treble of Brendan Rodgers’ second reign, against the same opponents he overcame to clinch his first in 2017. It would be the club’s ninth treble and their sixth in nine seasons.

Captain Callum McGregor started the rout in the 34th minute before setting up Daizen Maeda to net the first of two first-half goals, which came either side of Adam Idah’s tap-in. Substitute Jota rounded off the scoring midway through the second half.

Rodgers named the same team who also hit five goals past Kilmarnock last week, after making four changes in the wake of that defeat by Saints.

That meant a start for Idah, whose professionalism was defended by Rodgers after footage emerged on social media of the striker’s midweek night out, which appeared to show him being sick in a taxi.

It was one-way traffic from the start as James Forrest caused problems with several crosses and efforts at goal, while McGregor, Arne Engels and Maeda had long-range efforts saved.

Saints boss Simo Valakari would have been happy enough as his side denied Celtic space in behind but they played a part in the opener. Barry Douglas flighted a goal kick towards Stephen Duke-McKenna inside his own half and Alistair Johnston took advantage of the lack of pace on the ball to intercept.

The right-back fed Reo Hatate who set up McGregor to sidefoot the ball into the corner from 16 yards out for his 10th goal of the season.

The goalscorer drove forward three minutes later and played a pass just inside Sam Curtis for Maeda to slot into the far corner.

The favourites put the game beyond any doubt in the final minute of the half. Liam Scales split the Saints defence and Hatate squared for Idah to tap in, before the Japan midfielder provided another assist for Maeda to fire through a crowded goalmouth and into the bottom corner.

Idah should have made it five three minutes after the restart but appeared to get his foot caught in the turf as Forrest’s square pass rolled right in front of him in the six-yard box.

Valakari had brought on forwards Benji Kimpioka and Makenzie Kirk at half-time and the latter quickly grabbed the limelight, although not to any lasting impact.

The Northern Ireland Under-21 international forced a great save from Viljami Sinisalo with a mid-air flick but the offside flag went up.

Kirk then fired into the top corner from 25 yards but referee Calum Scott disallowed the goal following a VAR review after spotting a two-handed push on Idah from Daniels Badolis as Saints won possession.

Another VAR review saw Scott rescind a penalty award after Forrest eventually went down following a sliding challenge from Sven Sprangler and a shoulder charge from Badolis.

Idah had been set to take the penalty, but instead was one of three players to make way in a triple change.

One of the substitutes, Jota, soon squeezed the ball home inside Andy Fisher’s near post following Johnston’s deep cross.

The Premiership’s bottom club avoided further blows to their morale and Valakari handed Uche Ikpeazu his debut in the 75th minute as the striker finally made his comeback from knee surgery.