Hucknall were in the hunt until the middle of the final quarter when Otter held a slender 7-5 lead. Then a long break from her own half resulted in Niamhh Moloney scoring a fine goal for the London side - followed shortly afterwards by two more from Rebecca Mulcahy.
Earlier, Manchester were too strong for Liverpool Lizards, winning 16-6. Leading scorers were Rosie Huck (4), Brooke Tafazolli (3) and Harriet Dickens (3).