Last week’s man of the match Aussie Jim Perrett opened the scoring with only a couple of minutes on the clock following a break by winger Jack Anderson.
Fly-half Tom Harrison added the extras for a 7-0 lead.
The Seasiders never had things all their own way against a hard running Selby outfit but surged further ahead in the 19th minute with centre Tom Ratcliffe gliding over and Harrison converting for 14-0.
Ratcliffe then provided the pass for flying winger Jonty Holloway to race away and score his sixth try in three games, Harrison adding the goal for 21-0 in the 32nd minute.
Wing Harry Cruise pulled one back for the visitors and Mark Leetham converted to reduce the arrears at 21-7 before scrum-half Jordan Wakeham grabbed a signature opportunist try to win his side a bonus point and a 26-7 lead at the break.
Selby offered stiff resistance after the break and their hard-running could have produced more but for a superb defensive performance by skipper Matty Jones’s men.
Scarborough’s remaining tries all came in the third quarter with hooker Sam Dawson, Ratcliffe's second and Jack Anderson all crossing the whitewash following flowing three-quarters play; Harrison converted Dawson’s effort.
FULL REPORT PLUS PICTURES FROM ANDY STANDING IN THURSDAY’S SCARBOROUGH NEWS