The fight between the gladiator and Bree was not yet over. It had just barely begun. Embarrassed by being overwhelmed like that, the gladiator began to ran forward, holding his shield in front of his body in a way that it couldn't be pushed to the side.
But Bree didn't care much about that, she figured out her own tactics after analysing this situation sufficiently. Just before the gladiator came into range, Bree had swung her hammer down over her head. It seemed like she was planning not to hit the shield to the side, but to hit its top and push it down. The gladiator realised this as well, and pushed his foot into the ground to stop moving.
However, Bree was never aiming for that shield in the first place. Instead, she aimed at the ground in front of her. As the heavy hammer hit the floor and cracks formed on it, a cloud of dust appeared that surrounded both her and the gladiator.