For this game, the late unavailability of young prop Ryan Pickering resulted in Scarborough coach Lee Douglas having to reshuffle his front row with hooker Mark Hopper playing prop for the first time in his rugby career.
However the overall balance of the pack was improved by the return of the experienced Matty Else at No8.
With Corey Dennis nursing an injury, Billy Parker came in at centre with Graeme Jeffrey switching to full-back.
And the re-shuffled Seasiders were stunned with only five minutes gone when a superb miss-pass from Selby fly-half Dan Porter sent centre Pete Turner scampering over in wide on the left to open the scoring.
Rangy fullback Josh Cruise added the extras with a fine touchline conversion for a 7-0 lead.
Scarborough’s re-shuffled pack had the upper hand in the early exchanges with new-found prop Hopper and his front-row colleagues Ian Williams and Paul Taylor starting to dominate in the tight and also around the paddock.
Veteran pack-leader Nick Ingham was leading by example as the visiting back five looked to blast away the Selby mid-field defence.
With clean ball halfbacks Jordi Wakeham and Tom Chadwick quickly got their back line moving and winger Harry Domett made 40 metres up the right flank leaving a posse of would-be tacklers in his wake before being stopped illegally. Chadwick kicked the penalty to reduce the arrears at 7-3 in the 12th minute.
The visitors were very much on the front foot and a chip through by Wakeham almost led to a try in the 18th minute. However, following a slick move left to right on the home 22, wing Joe Marshall powered over in the corner to nudge the his side 8-7 ahead in the 20th minute. Chadwick failed to convert from the touchline.
With his siege-gun boot, Selby fullback Cruise made any infringement in the Scarborough half likely to be punished and when the Seasiders drifted offside on their own 10 metre line, the big number 15 effortlessly potted his long-range effort for a 10-8 lead in the 26th minute.
Penalties from Chadwick in the 31st and 40th minute saw the visitors lead 14-10 before a Cruise penalty in first-half injury-time reduced the arrears to a single point and Scarborough led 14-13 at the break.
Scarborough dominated from the re-start pushing the home eight off their own ball at the first scrum and when a bullocking run down the right flank by prop Paul Taylor rattled the home defence, the ebullient Billy Parker was there to barge over in the 43rd minute. Chadwick converted for a 21-13 lead.
Skipper Tom Ratcliffe’s men took the game by the scruff of the neck with the front five punching holes in midfield and Matty Oxtoby Paul White and Matty Else tiding up.
Behind them halfbacks Wakeham and Chadwick added the finesse to bring their backs into play.
Selby were no mugs however and defended well but at this stage possession was restricted by a dominant Scarborough pack and they tended to kick away what good ball they won.
An exchange of penalties between Cruise and Chadwick in the 47th and 50th minutes moved the score on to 24-16 before a mazy run by the latter left several defenders floundering and he scored wide on the right in the 52nd minute to stretch the lead to 29-16.
Going into the final quarter the Seasiders went close on several occasions with Domett, Marshall, Hopper, Parker and Ratcliffe in lively form. Trailing by 13 points Selby turned down several kickable penalties to go for touch but it was Scarborough who stretched their lead to 32-16 with a Chadwick penalty in the 70th minute.
With time running out Scarborough looked less positive as they ran down the clock with a long series of pick-and-go moves on halfway.
And this attitude and a late lapse in concentration could have cost them dearly as Selby threw caution to the wind in a storming finish which led to a second try for centre Pete Turner in the first minute of injury-time.
A touchdown for winger Ben Lunt with the last move of the game following some weary looking Scarborough tackling came after fully 85 minutes of second half action. Cruise kicked both conversions to produce a flattering 32-30 scoreline for the home side.
This was a thoroughly deserved win for all 18 Scarborough players who put in a committed shift on the road.
A terrific performance from the makeshift pack was the cornerstone of the victory with a battling back division with Chadwick, Domett, Parker and Wakeham outstanding.