THE Six Nations has reached boiling point after three rounds of action has left Ireland undefeated in pole position, with a grand slam beckoning.

Defending champions England were upended in a tumultuous tussle at Murrayfield, as the Scots were too strong at the breakdown and laser sharp in attack against them.

Wales lost for the second time, but the vagaries of the bonus point system leave them with an outside chance of the championship if other results go the right way for them.