Poly began the last period with a 7-6 lead but then conceded goals to Sam Bennett and Peter Farkas. A penalty by Andre Ferdinand levelled the score and there were just 23 seconds remaining when Michal Rybnikar scored for Solihull to clinch a 9-8 victory.
Welsh Wanderers' reliance on the firepower of Dan Laxton was underlined in their 12-8 defeat of Manchester Hawks - he scored nine times.