A fight billed as the most anticipated Scottish domestic clash for years did not disappoint as the Edinburgh's fighter got the nod following a thrilling east-versus-west unification battle.
The previously unbeaten Farooq, however, was left stunned by the decision of the judges, with two scoring it 114-113 and 115-112 in favour of Steel City gym’s McGregor and only one giving the Glaswegian their backing at 114-113.
What was even more remarkable was that McGregor, 22, was stripped of a point during the ninth round as he was forced to hold onto his opponent in a bid to slow the volley of punches breaking through his defences.
McGregor – under the guidance of Grant Smith – now extends his perfect record to 8-0.
The pair knew each other's styles inside out having previously roomed together during their days as team-mates on the Scottish amateur squad.
McGregor had a two-and-a-half inch height advantage on his opponent and looked to impose himself early in the first round with a barrage of right hooks, but Farooq's slippery head movement made him a difficult target to hit.
Farooq was quicker out of his corner in the second and momentarily wobbled McGregor with a left-right combination but recovered well, responding with a stinging straight right late in the round.
The fight had quickly broken into an absorbing tear-up. Another left hook from Farooq got the Glasgow faithful off their feet midway through the third but McGregor was undeterred as he continued to work well on the inside.
Rounds four and five saw both fighters trade a succession of thudding shots but increasingly it was Farooq's which seemed to land the cleaner punches.
The left hook was his weapon of choice and by round six it had left swelling under McGregor's right eye.
The Edinburgh fighter realised as round seven got under way that he had to up the pace and four huge uppercuts produced an almighty roar from the capital support.
With fatigue starting to become a factor, referee Victor Loughlin was forced to intervene and split the pair during the next stanza as tired arms tangled.
Farooq switched his attack to the body in the ninth, while McGregor got another talking to after he sent his rival tumbling through the ropes with a blatant shove.
That only seemed to annoy Farooq who upped his already tenacious work rate when the action resumed for round 10. McGregor was forced to cling on to his opponent in a bid to catch his breath but was punished with the removal of a point by the Loughlin.
McGregor feared that could be crucial so roared back as round 11 commenced, connecting with two hurtful lefts.
Both fighters showed their respect for each other as they embraced in the middle of the ring before the final round. That respect was again evident from Farooq as he stood toe-to-toe trading when he perhaps he should have stayed out of trouble.
But even he could not have expected to see McGregor's hand raised as the shock decision was read out.