Chasing 255 – the highest target in IPL playoff history – Gujarat never took off and were bowled out for 162 in 19.3 overs, unable to keep pace against Bengaluru's clinical bowling.
Put into bat, Bengaluru dominated the powerplay to reach 76-1 before Krunal Pandya and Patidar capitalised on favourable batting conditions at the picturesque Himachal Pradesh Cricket Association Stadium.
Gujarat, however, did not help their cause, putting down chances and conceding easy runs through sloppy fielding.
Patidar, who was put down on 20, made the most of the reprieve to finish as Bengaluru's top scorer with an unbeaten 93 off 33 balls, including five fours and nine sixes.
Rahul Tewatia led a late push with 68 off 43 in Gujarat's chase, but an early collapse to 51-5 in the powerplay proved costly. Rasikh Dar's double-wicket maiden was a highlight of the first six overs, while Jacob Duffy returned figures of 3-39.
Bengaluru will now play the final on Sunday, while Gujarat will have another chance to qualify when they face the winner of the eliminator in the second qualifier on Friday in Chandigarh.