Injuries to Spalding players took their toll as St Ives eased away in the final quarter of a pulsating game.
For 60 minutes this was a highly entertaining tie with two evenly-matched teams challenging each other with some excellent tries scored by the wingers.
Bouyed by last week’s home win against Birstall, they took to the field with only two changes as Kieran Bailey started at open side flanker and Tom Wilson came in at centre for Dan Adams.
St Ives started brightly and a ruck infringement saw the visitors take a three-point lead with a successful penalty.
Spalding followed the same game plan as last week and a break down the left wing involving Richard Cooke, Harry Brown and George Douglas ended with Gav Sharman running in for the opening try converted by Willis Ingleby.
Midway through the first half, StIves showed their pace and passing ability with both wingers scoring tries in the corner.
Spalding’s forwards put pressure on the St Ives try line but the defence stayed solid.
With a couple of scoring opportunities wasted through poor execution, the tables were turned as St Ives took their half-time lead to 13 points.
The opening five minutes of the second period saw Spalding hit back with some scintillating three-quarters play.
Excellent passing along the backs saw Sharman in at the corner.
Ashton Capes then lit up the afternoon – taking a pass on the halfway line and outpacing cover tackles to score by the posts with Ingleby converting for a one-point difference.
Injuries disrupted the home team with Ash Anker, Ash Piccaver, Jacob Hutson and George Douglas forced off.
With all the substitutes on the field and a few players out of position, Spalding’s cohesion was lost with the forwards tiring from their first-half efforts.
St Ives capitalised and pressure on the Spalding try line resulted in a three-on- two overlap for their next try.
Spalding’s scrum suffered and a turnover ball saw St Ives’ left-winger score in the corner.
Spalding’s penalty count against started to mount, giving away territory and possession as a lineout catch and drive brought further rewards for St Ives.
George Brown was the fifth player forced to leave the field and St Ives’ final try and conversion came from their scrum, driving forward.
Spalding: Turner, Rollinson, Hutson, Piccaver, H Brown, Anker, Bailey, Steels, Cooke, Ingleby, Sharman, G Brown, Wilson, Capes, Douglas. Subs Reid, Crowson, Shields.
Meanwhile, Bourne beat Skegness 28-0 and Deepings had a home walkover against Bingham.