Havant had their London one south play-off bid badly dented by a surprise 15-7 defeat at relegation-battling Chiswick on Saturday.
Head coach Will Knight accepts his side have given themselves a mountain to climb with four games left.
They remain second – three points ahead of Tunbridge Wells – but their closest rivals have a far easier run-in.
‘This result definitely makes it a lot more difficult for us,’ said Knight.
‘Tunbridge still have to play the bottom three teams and three of their final four games are at home.
‘We have a tougher finish, including a visit to leaders Sidcup on the last day of the season.
‘If anything, though, our squad have shown they can thrive on a little adversity.
‘The situation I am sure will spur them on but we know it is going to be tough.’
Havant began reasonably well but it was Chiswick who broke the deadlock 12 minutes before half-time.
The home side, who moved the ball quickly all game, spun the ball and got outside the Havant defence who were desperately trying to scramble across.
Havant, however, hit back to lead 7-5 at half-time when a good combination between forwards and backs ended with hooker Jerome Trail powering under the posts. Joel Knight added the conversion.
‘At half-time we felt we could put our foot down and take the game away from Chiswick,’ added Will Knight.
‘That didn’t happen for us. We made of lot of uncharacteristic errors and we ultimately paid the price.
‘Players got isolated or spilled the ball in contact situations.
‘We were getting on top of each other and lacked our usual organisation.
‘In reality we just didn’t perform and we lacked our usual rhythm.
‘It is hugely disappointing because we felt we had enough ability in our team to get the job done.
‘We just did not get it right on the day.
‘Chiswick played with the passion of a team fighting for their lives.’
The home side regained the lead 12 minutes into the second half of the match with a penalty for not releasing at the tackle.
Havant’s fate was then sealed 10 minutes from the end when Chiswick notched their second try.
The visitors seemed to have the attack covered but a perfectly-timed offload caught them out
With the conversion added, it meant the visitors needed to score twice in the last 10 minutes.
‘The more we chased the game the more errors were made,’ added a disappointed Knight.
‘We have to put it down as just a bad day at the office.’
n Havant Mariners are celebrating after beating Gosport & Fareham Vets 22-17 in the final of the John Sneezum Trophy at Hooks Lane.