The fly-half, on loan from part-timers Hull Ionians to ease the injury problems at Clifton Lane, slotted straight in on Saturday to help the South Yorkshire club a first victory in eight games.
Such was the Scotsman’s overall control and guile, it was no real surprise they led 23-3 at the break, his excellent kicking keeping the points ticking over and some quality handling also helping to set up half-back partner George Tresidder for a slick try.
Granted, Rotherham lost their way a little in the second period when the competition’s bottom side probed away at them relentlessly but, having not won since mid-November, there was not too much disquiet afterwards.
For Millar, it was a welcome – if possibly brief – return to Championship action, having left London Scottish at the end of last season.
The 25-year-old told The Yorkshire Post: “I really enjoyed it out there.
“Obvious it’s a step up from National One – it’s quicker, more physical – but the boys here made me feel welcome, I’ve fitted in quite well and it’s good to get go a good win as well.
“It has been different this year from training every day (at Scottish) to just nights now at Hull Ionians. I had to get a full-time job on top of it. I’ve been doing bits and bobs for my girlfriend’s dad helping him out.
“He’s a landscape gardener so I’ve been doing a bit of labouring for him when needed.
“He’s kept me ticking over and he’s been flexible with rugby if needs be, too. It was a nice change at the time (joining Hull) as I was out with injury last year at Scottish so it’s been good to get regular games as well.
“But it’s been nice to get back into the Championship as well today.”
It remains to be seen if Millar’s services will be called upon again for Sunday’s derby at high-flying Yorkshire Carnegie but head coach Justin Burnell was certainly impressed with his contribution at the weekend.
Millar and Rob Kirby exchanged early penalties before Tresidder showed great pace to finish off the crisp midfield move initiated by Millar, who duly converted.
He added another penalty before a well-worked line-out drive saw No 8 Tom MacDonald rumble over in the 22nd minute, Millar smartly improving from wide out.
Although they soon lost lock Oli Curry to a yellow card for a blatant professional foul, that did not unsettle them as Burnell’s side encouragingly showed true grit to keep Richmond out during his absence.
He added a third penalty on the stroke of half-time, maintaining his 100 per cent record, but that would be the last of Rotherham’s scoring as their opponents, with just two Championship wins since earning promotion, dominated large periods of the second half.
They scored a well-earned try in the 67th minute when some smart hands out wide saw centre Cameron Mitchell cross, Kirby converting, but it did not signal any form of collapse for the hosts.
This game, of course, was initially all set to be a vital game in the battle to avoid the drop but last week’s announcement that London Welsh had been jettisoned from the league and there would be no relegation in 2016-17 eased pressure somewhat.
Nevertheless, it was not obvious to see as both sides approached the fixture with real determination and physicality.
Millar admitted: “Just because there’s no relegation, that doesn’t matter. You still need to win games; it’s a professional environment at the end of the day.
“That’s how we looked at it and Rotherham want to start building now, win some more and finish above bottom. This was definitely a game of two halves. We dominated the first one but the wind was stronger than you think playing into it. In the second half, we fell off the gas and let them come at us a bit too much but overall it’s good to get the ‘W’.
“I’m not sure what the future is for me. Basically, I came in for this game and had trained the last couple of weeks but we’ll see what happens.
“It has been really good, though, and an easy transition. The boys have helped me out with the calls and it’s a good, friendly club.
“Carnegie will be a big game for the boys again but, after this, they’ll be looking to push on for another win and get a good performance under their belts.”
Rotherham Titans: Thomas; Foley, Wilson (Kelly 79), Barker (Owen 57), Henry; Millar, Tressider; Tom Williams (Toby Williams 60), Maddison, Rees (Herriott 71), Salmon, Curry (Hicks 69-Graham 76), Lawrence, Calladine, MacDonald (Tyas 69).
Richmond: Kirby; Woodward, Mitchell, McLean, Cheesman (Browne 77); Damant (Gabbitass 78), Stuart (Gibbs 78); Cunnew (Tarrant 62), Grimstone (Townsend 68), Harden, Warden (Walford 70), Corker, Peters, Allcock, Edwards (Davies 57).
Referee: T Foley (RFU).