Bailey Peacock-Farrell producing one of the best penalty saves you will witness all season, to deny Kieran Sadlier at the end of an opening 45 minutes which the Millers had been the better side but neither side could conjure a goal.
If the Owls custodian deserved his man-of-the-match award for that save, his opposite number Viktor Johannson will not want to watch the highlights from this game.
With the contest in the balance, despite Florian Kamberi’s opener for Wednesday on 49 minutes, the Rotherham United goalkeeper somehow failed to grasp a timid long-range shot from Dennis Adeniran, and Lee Gregory pounced to make it 2-0 in front of a 11,522 crowd.
Never has the fortunes of the goalkeeping union differed in the space of 45 minutes.
The hosts recalled captain Richard Wood to face his former club, while Sam Hutchinson missed out for the Owls, Chey Dunkley starting, while midfielder Massimo Luongo made his first start in 2021.
The 28-year-old Australian last started a game on December 8 2020 – a 2-0 defeat at Huddersfield Town in the Championship – so this was a welcome return after a spate of injuries.
Kick-off was delayed for 15 minutes at the sell-out AESSEAL New York Stadium.
Both of these teams – relegated last season, but favourites to bounce back at the first attempt – had made similar starts to life in League One, winning two of their opening three games.
But it was the hosts who made the better start, Ben Wiles firing over before Josh Kayode failed to test Peacock-Farrell with his header.
At the other end, Callum Paterson dribbled into the box, but Kamberi smashed his shot off target.
Rotherham were forced into an early change after 24 minutes, Chiedozie Ogbene limping off to be replaced by Sadlier.
After a frenetic opening half hour, when the hosts’ high-pressing play rushed the Owls into mistakes – and Rotherham spurned several good chances to open the scoring - the match started to calm down.
But the Millers had a glorious chance to take the lead before half-time.
Paterson brought down Kayode for a penalty, but Peacock-Farrell produced a stunning save to deny Sadlier.
There was nothing wrong with the spot-kick, Sadlier hammered it inside the goalkeeper’s right-hand post, the ball was rising, but Peacock-Farrell – the former Leeds United goalkeeper – guessed right, and somehow tipped the ball wide in front of the 2,608 travelling away fans.
Four minutes into the second half and the visitors took the lead.
Paterson squeezed down the right, from a Luongo pass, and picked out the unmarked Kamberi who fired the ball into the roof of the net for his first goal in Owls colours.
It was to prove Kamberi’s last meaningful contribution, Darren Moore making a double substitution, bringing on Gregory and Adeniran, with Lewis Wing – having been booked in the first half – also departing.
With the rain now pouring down, Paul Warne brought on Freddie Ladapo, the striker who netted the late winner at Hillsborough last season.
Wednesday spurned a chance to make it 2-0, Bannan releasing Gregory, with the visitors two against one on the counter-attack, but the striker’s touch was too heavy and allowed Viktor Johansson to get off his line and block the shot.
But it was 2-0 on 77 minutes, Johansson somehow failed to deal with Adeniran’s tame shot and Gregory pounced to tap into an empty net.
Rotherham United: Johansson, Ihiekwe, Wood, Harding, Ogbene (Sadlier 24), Lindsay, Wiles, Rathbone (Barlaser 72), Ferguson, Kayode (Ladapo 63), Smith. Unused substitutes: Vickers, Mattock, Miller, Edmonds-Green.
Sheffield Wednesday: Peacock-Farrell, Hunt, Iorfa, Dunkley, Palmer, Brown, Bannan, Luongo, Wing (Adeniran 58), Kamberi (Gregory 58), Paterson. Unused substitutes: Wildsmith, Byers, Dele-Bashiru, Johnson, Corbeanu.
Referee: M Edwards (Tyne & Wear).