Reigning champion Price recovered to overcome Danny Noppert in a gruelling tussle, while Van Barneveld produced a stirring fightback to stun Simon Whitlock.
Van Barneveld – a Grand Slam winner in 2012 – rolled back the years to defeat reigning champion Gerwyn Price in a deciding-leg thriller in their second Group A contest.
Welsh ace Clayton is yet to drop a leg in this year’s Grand Slam, making it back-to-back whitewash wins in Wolverhampton after sweeping aside Jermaine Wattimena