The Midlanders led 3-2 after two periods, but there was no more scoring until the game really came to life in the last period. Goals by 17-year-old Danica Brazier (2) and Claudia Ferrone then put Otter 5-3 up before Coventry levelled it at 5-5 with goals a couple of minutes from the end by Sally Rangecroft and Fran Clayton.
Bernice Cowton's experience was a big factor in Sheffield Sharks' 19-10 victory over Hucknall - she scored seven.