Annalys took possession of the ball and hit it up and down the field while Serena gave chase.
Serena attempted to steal the ball several times but could not successfully do so. However, she wouldn't give up as she doesn't want to lose to Annalys in any way. So, she persevered and when they were finally shoulder to shoulder, Serena attempted for a hook, and Annalys was unable to hit the ball.
The ball was left on the ground, but that's not the most pressing concern.
Everyone was focused on the ongoing game, that as soon as Christopher was able to gain possession of the ball, all eyes followed. So, they did not notice fast enough what was happening (not that they could have stopped it either as it's so fast).