St Ives saw their hopes of a second successive promotion dented by a disappointing Midlands Division two East (South) defeat last Saturday.
A 27-17 reverse at relegation-battlers Vipers provided one of few low points in a terrific debut season for the Bulls at this level.
The setback, which left them nine points behind second-placed Market Harborough with only four games to go, was all the more frustrating given it arrived only a week after a stunning success at table-toppers Olney.
The Bulls never looked like hitting the heights of that performance in their latest outing, although a Paul Ashbridge penalty put them ahead against the run of play.
But they were behind at the break after conceding a try and a penalty and that 8-3 deficit increased with another score for the hosts – this time converted – early in the second period.
Captain Ollie Bartlett was the beneficiary of fine work from player-coach John Naylor and Ben Fleming as St Ives responded with a try of their own which was converted by Ashbridge.
But it didn’t provide a springboard for a comeback as Vipers touched down on two more occasions before Ashbridge darted under the posts to provide a late consolation for the Bulls.
Director of Rugby, Phil Brown said: “We’re naturally disappointed we couldn’t back up the great win against Olney.
“We’ve had close games against Vipers in previous seasons, so maybe this was their turn to get a win. They certainly played better than us in key areas.
“But we’ll stay positive and look to finish the season well. We’ve already exceeded our original target for this season, so no-one is downbeat – and we have a cup final to look forward to as well!”
St Ives return to action on March 23 when they host Corby side Stewarts & Lloyds.