The 18-year-old was one of three Gers youth players to make the starting XI at the Dumbarton Football Stadium, alongside Tom Walsh and Andy Murdoch, and his two goals were key as the Ibrox side came from behind to move four points clear of Hibernian in the play-off race.
In a frantic opening few minutes the visitors threatened first when Haris Vuckic picked out Nicky Clark but the striker sent the ball over the bar from eight yards out
The home side took advantage of that miss and immediately took the lead after just two minutes when ex-Celtic man Mark Wilson got on the end of Mark Gilhaney’s cross to the back post to volley past Cammy Bell in the Rangers goal.
Gers skipper Lee McCulloch was next to go close for the away side but his acrobatic effort was pushed over the bar by Danny Rogers before the Sons keeper denied Nicky Law.
However, the visitors’ pressure paid off and it was Hardie who got the equaliser. The on-loan Vuckic slid a ball through to the youngster whose initial effort was blocked before he poked home the follow-up.
Rangers continued to press and the home side again had Rogers to thank after 12 minutes when Darren McGregor’s long-range effort was saved by the goalkeeper.
The sides then traded chances, though the Sons’ Dylan Easton and Tom Walsh but both shot off target before Rogers was called into action again to push Law’s effort over the bar.
Rangers came out after the interval and killed the game within the first 10 minutes of the half. Hardie was making a big impression on his first start for the Light Blues, and he got his second when he picked up on Lee Wallace’s cross and hooked his effort over his shoulder with his back to goal, guiding the ball past Rogers.
Minutes later, Vuckic got his seventh goal in nine games when he cut in from the right before beating the Dumbarton ‘keeper with a ferocious strike from distance.
Bell was then forced into a good save from close range when Stuart Findlay met Easton’s delivery but he could not beat the Gers ‘keeper.
Nicky Law nearly made it 4-1 with five minutes remaining but his effort from the edge of the box clipped the bar.