Tubbs admitted finishing as League Two’s top goalscorer is firmly on his mind after helping the Blues to a 2-1 win at Mansfield Town.
The striker took over penalty duties from Jed Wallace to take his league tally for the campaign to 20.
It also helped the Blues to just their third league win on the road this season – and Gary Waddock to a first success as caretaker boss.
Tubbs is now two goals clear of Northampton’s Marc Richards, Dagenham & Redbridge’s Jamie Cureton and Plymouth Argyle’s Reuben Reid in the race for the golden boot.
Eight goals have arrived since signing from AFC Wimbledon in January, with the 30-year-old bagging 23 strikes in all competitions.
Tubbs thanked Pompey’s other goalscorer, Wallace, for stepping away from Saturday’s penalty against the Stags to help his cause.
And the Blues predator is now out to continue in the same vein as the curtain comes down on the campaign against York City at Fratton Park on Saturday.
Tubbs said: ‘Jed is the penalty taker but I’m in the situation where I want that golden boot.
‘Jed knows that, so a lot of credit has to go to him for being the penalty taker and letting me take it.
‘I’ve still got something to play for in the game to come.
‘Of course I want the golden boot. When I started the season at Wimbledon I was telling people I wanted it.
‘If you go through the season and don’t aim high you won’t achieve anything.
‘I’m never going to be the player who is going to beat three people and stick the ball in the top corner.
‘If you look at my goals, you wouldn’t have seen one outside of the penalty area.
‘That’s not my game. I operate in and around the six-yard box and in the area.
‘In the Conference I won the golden boot and I was also joint winner.
‘So I’ve got one-and-a-half golden boots if you like.
‘Now I have 90 minutes of football where I have to get over the line.’
Tubbs was delighted for Waddock as he picked up his first success since taking over the reins from Andy Awford three games ago.
The striker feels the players are responding to the caretaker boss’s desire to play an expansive game.
Tubbs said: ‘Knowing the type of person Gary is, he would have wanted four wins out of four.
‘If we can give him two out four that would be great.
‘He’s come in and put his own stamp on things.
‘He wants to play out from the back, which is different to when Andy (Awford) was here.
‘I know people who were with him at Aldershot and that was the way he wanted to play there. We have to do that for him as players.’