Celtic have set up a Scottish Cup final meeting with Aberdeen after beating Rangers 2-0 at Hampden Park.
Callum McGregor opened the scoring for the Hoops in the 11th minute when he cleverly slotted the ball past a stationary Wes Foderingham.
Celtic dominated the opening half, but were dealt a blow when Moussa Dembele pulled up with a hamstring injury and had to be replaced by Leigh Griffiths.
The clinching goal for Celtic then came six minutes after the restart, James Tavernier bringing down Griffiths in the box to earn Brendan Rodgers's side a penalty.
Scott Sinclair, who has 20 league goals to his name this term, stepped up and confidently blasted his spot kick past the Rangers goalkeeper to send the Bhoys fans into delirium.
Kenny Miller saw a downward header from Tavernier's cross well saved low to his right by Craig Gordon, while the former Celtic striker drew a smart stop from the Scotland goalkeeper's feet later in the half.
Rangers, who lost for the first time under boss Pedro Caixinha, never really looked like mounting a comeback and Celtic - beaten by the Gers at the same stage last season - almost had a third when Tom Rogic rifled a late effort against the post.
The victory, Celtic's first Scottish Cup semi-final triumph over their Glasgow rivals since 1925, moved the club a step closer to their first domestic treble since 2001, with the title and League Cup already secured.