Both teams began the match knowing that victory would earn promotion alongside champions Manchester Hawks and Cheltenham Spartans and condemn the losers to a year in Division 4. For much of the time, Rotherham held the lead - 3-1 after the first period, then 6-3 half way through the third.
Otter then hit back, recovering to 8-8 two minutes into the final quarter thanks to goals by Denes Csizsinszky, Pier Spagna, Omiras Pantazis (2) and Orion Ganase. Rotherham went ahead once again at 9-8 with a fourth goal of the game by Richard Leighton. But Otter dominated the final stages, scoring again through Pantazis, Csizsinszky and Ganese. Birmingham's second defeat of the weekend - 18-13 against Bridgefield - ended their hopes of promotion.
In women's Championship 1 at Northampton, Caledonia beat Hucknall 8-4 to clinch second place behind Leeds Sharks.
Photo (Trevor Hyde): Leeds girls with their trophy. Back row (L-R): Ellie Sowerby, coach Mark Sutcliffe, Tegan Stanbach, Aubrie Monahan. Third row: Emily Sutcliffe, Minnie Gale, Isabel Larder. Second: Emily Pilkington, Emma Little, Kate Teasdale, Evelyn Larder. Front: Joe Duncan, Sophie Jackson.