Pompey’s opening goal against Oxford started with a Connor Ronan corner.
His cross was headed back into the centre by Matt Clarke, where Kal Naismith was waiting to hook the ball home.
It helped lay the foundations for 3-0 victory at Fratton Park, with Brett Pitman adding a brace in the second half.
And the goalscorer wants to see the Blues making more of their set-piece opportunities in the future.
Naismith said: “I’m delighted because I haven’t scored in a while – it’s been too long. It was a great volley!
“It came from a corner and I think we need to score more from set-pieces because we’ve got some big lads in the team.
"We work on them a lot – trying to hit good areas. There are some great deliveries and it’s nice to see one come off.”
“Guys like Matt Clarke, Jack Whatmough – Christian Burgess when he plays – attack the ball very well.
“Jamal Lowe and I both took a gamble and he just missed it, but happy days because I’ll take them from just a yard out.
“We work on them a lot – trying to hit good areas. There are some great deliveries and it’s nice to see one come off.”
Pompey only had a slender lead when Alex Mowatt’s penalty struck the post, with the Oxford player then immediately being dismissed for lashing out at Nathan Thompson.
Naismith said: “It’s crazy how games can swing because if they’d scored that then they would have been right in the match.
“The boy’s unlucky because he struck it well, but it’s come back out off the post and he’s obviously frustrated.
“Nathan got in his face a bit and he’s reacted by lashing out. He shouldn’t have done it, although you can understand why he did. It’s a bad minute for the lad.
“The game opened up when they went down to 10 men and we were able to capitalise by getting two more goals.
“Results here haven’t been good enough lately, but when the fans are behind you this is a tough place to come and we’re delighted to be building a bit of momentum.”