The England star scored three tries and was successful with five from eight conversions, while team-mates Lewis Dodd and Sione Mata’utia each grabbed braces and Alex Walmsley added another to hand Saints their fourth-successive win.
League leaders St Helens are gunning for a record fourth consecutive Grand Final victory and showed few signs of slowing down in their eight-try romp at Sewell Group Craven Park.
It took just three minutes for Kristian Woolf’s men to strike, second-rower Mata’utia crashing through some soft tackling to score and Makinson nailing the conversion to make it 6-0.
In the 16th minute, centre Konrad Hurrell was sent to the sin-bin for a late hit on Hull KR half-back Jordan Abdull.
Twelve-men St Helens managed to withstand a wave of Rovers attacks to keep their try-line intact, until winger Ryan Hall dived over in the corner after 22 minutes thanks to a brilliant cutout pass from former Saints star Lachlan Coote.
Abdull missed his conversion attempt from the sideline, but Makinson was the next to cross, touching down for his 150th career try for Saints after a lovely pass from full-back Jack Welsby.
The winger’s conversion was on target from out wide to give his team an eight-point buffer.
Three minutes later, the defending champions were in again, this time Dodd skipping past some slow defenders with a magical run to score his first try of the night. Makinson added the extras to make it a commanding 18-4 lead for Saints heading towards the break.
But it got worse for under-pressure hosts just a minute before half-time when Dodd brought up his brace, after a clever grubber kick from Welsby wrongfooted the Rovers defence and the young half-back won the race to the ball.
Makinson’s fourth successful conversion took the score to 24-4 and put them in the driving seat at the interval.
In the second half, the carnage continued for Rovers with second-rower Mata’utia quickly barging over again in textbook fashion for his second try.
Makinson’s perfect evening with the boot ended as he hooked his first conversion wide.
But eight minutes later, the winger crossed for his own double, dancing down the sideline from Mata’utia’s bullet pass untouched for St Helens’ sixth try.
The England international’s kick bounced off the post and over to take the lead to 34-4.
The nail in the coffin came with 16 minutes remaining when prop Walmsley bulldozed his way over, with Makinson failing to convert the final St Helens score.
Then Frankie Halton crossed off Abdull’s kick for a Hull KR consolation try before Makinson touched down late to bring up his hat-trick.
Hull K R: Coote, Wood, Takairangi, Kenny-Dowall, Hall, Lewis, Abdull, Vete, Parcell, King, Hadley, Halton, Storton. Substitutes: Litten, Sims, Minchella, Dagger.
St Helens: Welsby, Hopoate, Hurrell, Percival, Makinson, Lomax, Dodd, Walmsley, Roby, Lees, Mata’utia, Batchelor, Knowles. Substitutes: Lussick, McCarthy-Scarsbrook, Pa’asi, Amor.
Referee: James Child (RFL).