The Gas Monkey Garage BMW by FHO Racing rider led every lap of the six-lap showpiece, which was postponed from Friday due to poor weather on the island.
Hickman’s winning margin was 19.6s over 2019 Senior TT winner Dean Harrison on the DAO Racing Kawasaki, while Manxman Conor Cummins edged out his Milenco by Padgett’s Honda team-mate Davey Todd by 2.8s for the final rostrum place after a race-long battle.
BSB contender Hickman has now moved level with David Jefferies and is only one victory behind Giacomo Agostini and two adrift of Steve Hislop and Phillip McCallen on the roll of honour.
He has also joined an elite group of riders who have won four or more TT races in a week, including McCallen and Michael Dunlop, plus Ian Hutchinson, who is the only rider to win five races in a week.
The 35-year-old set the fastest lap of the race at 132.504mph on his second lap, with high winds on the Mountain keeping speeds down.
Northern Ireland’s Michael Dunlop, who won both Supersport races to move onto 21 wins, finished fifth on the Hawk Racing Suzuki, 1m 42s down on Todd, with OMG Yamaha’s James Hillier completing the top six, 11 seconds behind Dunlop.
Ian Hutchinson was seventh on the Milwaukee BMW, with Jamie Coward (KTS/Steadplan Yamaha), John McGuinness (Honda Racing UK) and Manx rider Nathan Harrison (IoM Steam Packet Honda) – competing in his first TT – rounding out the top 10.
McGuinness received a 10-second penalty for speeding in pitlane during his first pit-stop.
His team-mate, Glenn Irwin – who set the fastest ever lap by a TT newcomer in the RST Superbike race at 129.85mph – was a retirement after the second lap in the pits while holding tenth place. The 32-year-old pulled out of the race with an issue on his CBR1000RR-R Fireblade.
Shaun Anderson from Banbridge was 12th on the Crendon Hawk Suzuki behind Craig Neve (Callmac Scaffolding BMW), while Derek Sheils was the leading Republic of Ireland rider on the Roadhouse Macau BMW in 15th.
Brian McCormack (Roadhouse Macau BMW by FHO Racing BMW) and Mike Browne (Burrows Engineering/RK Racing Suzuki) both retired from the race.
Magherafelt’s Paul Jordan also retired on the PreZ Racing Yamaha after feeling unwell.
Lee Johnston was a non-starter on the Ashcourt Racing BMW as he continues to struggle with an issue affecting his eyesight.
Newcastle’s Dominic Herbertson crashed at Glen Helen and was airlifted to Noble’s Hospital. Herbertson was initially reported to be conscious with hip injuries.