Pompey Ladies beat Keynsham 3-2 to boost confidence ahead of the big match with Spurs at Fratton Park on Sunday.
Lauren Murphy and Gemma Hillier put the Blues in command of the FA Women’s Premier League southern division clash.
But Keynsham battled back to level the clash at Hayling United’s College Ground.
After the Blues missed a chance to regain the lead when Charley Wilson was unable to convert a spot-kick, it took a Sarah Kempson penalty in the 94th minute to settle the contest.
That makes it three wins on the trot for the Blues ahead of the much-anticipated first ever Fratton Park ladies’ league match.
Joint Pompey manager Katie Poore was happy to get the win.
But she felt it should have been easier than it proved in the end.
Poore said: ‘We deserved to win but it looked like it was going to be one of those games where it doesn’t pan out like that.
‘We were 2-0 up after 15 minutes.
‘Then we made hard work of it.
‘It was a real battle in the second half, after it looked like we were going to coast it.’
Defender Murphy got the opener on four minutes when she knocked the ball home after a scramble, following a corner.
Pompey doubled the lead in the 14th minute thanks to skipper Hillier.
Jess Frampton’s shot was parried by the keeper and Hillier reacted sharply to latch onto the loose ball and net from a tight angle.
Keynsham struck a goal back on 30 minutes.
The Blues regrouped for the second half and started to dominate the play again.
But Keynsham counter-attacked to win a corner and found the net with a header as Hillier was just unable to clear the ball off the line.
With 20 minutes to play, Pompey won a penalty when Kempson’s free-kick was handled by a Keynsham defender in the wall.
Striker Wilson stepped up but saw her spot-kick saved.
Fortunately for the Blues, they were handed another chance to secure the points.
Substitute Tiff Taylor was dragged down in the box.
Kempson stepped up this time, to slot the ball into the bottom left-hand corner.
The referee then immediately blew the final whistle.
Pompey are now looking forward to their Fratton Park clash with Spurs on Sunday (2pm).
Entrance is £5 for adults and £1 for concessions and a family ticket, for two adults and two children, costs £10.
Tickets are on sale from the Fratton Park box office and online.
See portsmouthfc.co.uk for details of sponsorship, hospitality and family Sunday lunch packages available for the game.