The former Wakefield Wildcats, Castleford Tigers and Huddersfield Giants player, who is now a budding actor, could face prison over the incident in Birstall.
Leeds Magistrates’ Court heard on Monday how Mason, 33, was in a Nissan Qashqai 4x4 on the afternoon of August 9 last year when an off-duty police officer spotted him driving erratically on Halifax Road in Staincliffe, near Batley.
She was so concerned he was going to hit her, she pulled over to let him past.
Five minutes later Katie Galvin, who was in her Mini Cooper with her daughters aged eight and 11, saw Mason coming towards her on Cambridge Road in Birstall.
Michael Miles, prosecuting, said Mason was travelling so quickly that his car bounced off the road at one point after hitting a speed hump.
Ms Galvin pulled her car to the side of the road, but Mason drove directly at her and appeared to accelerate before crashing into her.
Mr Miles told the court: “Both drivers got out and passersby gathered at the scene.
“Mr Mason walked away from the scene and didn’t make any attempt to exchange details with the driver of the Mini.
“One member of the public told him to stay at the scene or he would be in trouble.”
Mason later told police he went to his nearby sister’s house where he “collapsed onto the bed”. Mr Miles said: “He slept for five or six hours and didn’t report the matter to police.”
Ms Galvin suffered slight injuries in the incident.
Mason, who failed to attend court, was found guilty in his absence of careless driving, leaving the scene of a collision and failing to exchange details.
Sentencing was adjourned until February 3.
Mason could face up to 26 weeks in prison.