In a game where the Light Blues controlled proceedings, Chelsea Cornet popped up seven minutes from time to break the deadlock and spark scenes of jubilation in the Rangers corner.
Kirsty Howat then put the seal on the victory for the Gers, latching onto a defensive lapse to confidently lift the ball over the Celtic goalkeeper and seal her side’s place in next month’s final.
The Gers will now await the winners of Hearts and Spartans in the corresponding semi-final tomorrow afternoon.
Rangers were immediately in control from the outset as Jane Ross, restored to the side this afternoon, swivelled sharply inside the Celtic penalty area before arrowing a dangerous effort inches wide of the far post inside two minutes.
There was a calmness to Rangers’ play in the opening exchanges as they continued to put Celtic on the back foot. On 11 minutes, it was Rachel Rowe who burst through a gap in the opposition’s midfield that was thwarted just on the edge of the penalty area.
Opportunities to threaten the Celtic goal had been few and far between in the opening half-hour, but Rangers cranked up the intensity moments later with a flurry of chances.
Firstly, a lovely jinking run inside from Brogan Hay allowed the winger to feed a pass with the outside of her boot into Sarah Ewens, although the forward was unable to bring the ball under her spell.
Next, Mia McAulay popped up on the edge of the penalty area and, when her initial effort was blocked and fell kindly to Ewens, the 32-year-old dragged her effort wide of the target on her unfavoured left side.
Rangers were successfully stifling their opponents, going close once again when Rowe unleashed a venomous strike 25 yards that looked destined for the top corner before Chloe Craig took the ball square on her head.
Celtic emerged from the interval with a greater purpose, causing some anxiety inside the Gers penalty area when Celya Barclais hit the byline and centred in search of Murphy Agnew that Rangers were forced to hack away at the near post.
Down the opposite end and Rangers continued to pose a threat without the required cutting edge; Ewens firing over after Rowe did tremendously to steal possession inside the Celtic defensive third.
Jo Potter turned to her bench just shy of the hour-mark as the duo of Kirsty Howat and Rio Hardy, so prolific when paired together, were introduced in place of Ewens and Jane Ross.
Slowly but surely, the contest was beginning to stretch as we entered the final 20 minutes. Indeed, Chelsea Cornet tested her luck from 30 yards when space opened up infront of the Celtic penalty area, but Kelsey Daugherty was sufficiently alert to tip the ball over the crossbar.
It took 69 minutes for Celtic to truly trouble the Rangers goal on the afternoon as Tash Flint caught a bouncing ball on the full volley that whisked past Esson’s near post.
The moment served as a warning sign for Potter’s side that, despite their dominance of the ball, they still had to keep the back door shut.
Immediately, the Gers went on the attack and they were almost indebted to a wonderful solo effort from Rowe when she spun in midfield and dragged her finish wide of the Celtic goal.
The Welsh international was beginning to pur in midfield, and she almost helped break the deadlock when, after another confident swivel in the centre of the pitch, she slid a well-weighted pass through to Howat. The forward had only Daugherty to beat between the posts, but the ball appeared to run away from her and the Celtic goalkeeper was able to smother just inside the penalty area.
And the pressure eventually told for those in royal blue as the breakthrough arrived seven minutes from time. After Lizzie Arnot’s dipping effort was deflected out for a corner, Rowe’s resulting delivery was on the money for Cornet to sneak round at the front post and guide a header beyond Daugherty.
Rangers then made sure of the victory moments later as Howat showed tremendous opportunism to latch onto a defensive lapse from Celtic and lift a delightful lob over Daugherty.
RANGERS: Esson, Docherty, McLauchlan (Middag, 81), Hill, Hay (Arnot, 74), Rowe, Ross (Howat, 57), McAulay, Ewens (Hardy, 57), Cornet, McLoughlin
Subs not used: Fife, Bance, Austin, Martinez, McLeary
CELTIC: Daugherty, Barclais (Smith, 81), Ross, Craig, Mengyu Shen, Cavanagh (Gallacher, 45), Agnew (Burchill, 77), Clark, Hayes, Ashworth-Clifford, Flint
Subs not used: Logan, Cummings, Robertson, Menglu Shen, Goldie, McAneny