Ben Barnes felt Fareham lost their cool in the heat of battle as they went down 5-1 at Indian Gymkhana in National League conference west.
James Seager put Fareham 1-0 up early on and they had chances to extend that advantage.
But Gymkhana hit back to level just before the break and then it all unravelled for Fareham in the second half.
Fareham coach Barnes said: ‘After a bright start our lack of discipline cost us the game when a few decisions went against us which is disappointing.
‘We also turned over possession too often and enabled Indian Gymkhana to punish us and take control of the game in the second half, after we had created enough chances in the first half to go into half-time ahead.
‘We have to learn from this quickly.’
Seager found the net on nine minutes, following a fine run from Ed Carson down the right flank.
Fareham continued to dominate the play leading up to half-time, creating a number of good chances through Ben Hibberd and Carson which they failed to take.
As half-time approached, Fareham became over ambitious and paid for giving away possession in pursuit of extending their lead.
Instead the visitors made it 1-1 before the break.
They then struck four goals in the second half, while Fareham were rattled by a number of umpiring decisions that went against them.
In South Club Women’s League division one, Havant lost 7-2 at Tulse Hill & Dulwich.
Nicky Atkins and Hollie Smith fired the consolation goals for Havant.
Meanwhile, in South Club Women’s League division three B, Fareham lost 2-0 to Basingstoke.