The former England frontman broke a seven-match goal drought when he secured a 1-1 draw against Derby last weekend to edge Pompey another point clear of the relegation zone.
"It's my first goal for a while now and I just need to keep on going," he said.
"I'm on nine now and want to get into double figures.
"It's a confidence boost for the whole side. It's a point on the board and the bottom three all lost.
"It's a start but now we're looking forward to the next game."