Their match day plans were upset during the warm up when vice-captain Liam Wilkinson aggravated a recurring ankle injury.
Not long into the match, they were forced to rejig the side for a second time when full back Matt Yuill limped off.
Yuill’s departure saw captain Marc Yeates move from his new home at No 8 to make a welcome return to his old berth at fly half.
Before the enforced changes, winger Aaron Goodman had opened Tows account by finishing a move wide out.
Spalding countered with a try of their own as they punished hesitation over a bouncing ball in order to level the scores at 5-5.
Taking over the kicking duties from Yuill, James Falvey capitalised on Spalding’s ill-discipline through two penalties.
Tows scrum, through front row Joe chambers, Richard Tustian and John Causebrook, began to dominate their opponents.
But despite creaking under the weight of the drive from the hosts, Spalding managed to survive a series of scrums on their line before half time.
Tows centre Martyn Harvey made a try saving tackle to keep Spalding out and he and Matt Bodily made barn storming runs through the middle.
With Tows pack now in control and lock Sam Sturly soaring high in the line out to win clean ball, Tows had the set piece sewn up.
From a line-out on the 22, Sturly rose again to claim possession. His pack launched a rolling maul at the line and hooker Tustian broke free two metres short to score.
Falvey landed the conversion from wide and soon after added a penalty to give the hosts some comfort at 21-7.
But Spalding weren’t finished yet. They hit back with a converted try when Tows’ backs dithered over a spilled ball and began to exert pressure through their backs.
Tows managed to hold on and the relief of the final whistle was tangible with the players cheering their win.