Roger Benz II

If a runner is attempting to reach a base and being chased by the defensive player. Base runner goes into a slide late and his momentum has caked himpartially past the bag. The fielder also dives forward attempting to make a tag and goes into a head first slide. The fielder reaches the runner just after the runner reaches the bag and the collective momentum carries them past the bag, runner is tagged and called out. It appeared the runner might have been able to stop while still in contact with the bag but his momentum was still moving forward when contact was made by the fielder. Should the runner be called out or would this be the runner was forced off the base by the fielder and awarded the base.