The Blues defender believes goalkeeper coach Joe Prodomo has to take much of the credit for his run of excellent deliveries leading to goals.
Sparkes was once again the architect of Conor Shaughnessy’s stoppage-time header which delivered a 1-0 win against Carlisle - Pompey’s seventh win on the spin.
The 23-year-old produced an outstanding sixth assist of the season in all competitions, to allow Shaughnessy to lift the roof of Fratton Park with his header.
Sparkes feels Prodomo’s detail has much to do with that success, as he puts in the preparation and comes up with the routines which have reaped dividends.
He said: ‘My crossing is an attribute and something I take pride in. It (set-pieces) is something I work on and we work on in training.
‘Joe (Prodomo) takes a lot of pride in that, so credit to him. He comes up with the routines and who does what in the box. Then it’s credit to the boys for doing it.
‘They (set-pieces) are big. We defend set-pieces well and always give ourselves a chance of nicking a goal by doing it at the other end.’
The late, late goals was their fourth in stoppage time this season - earning eight league points along the way. Sparkes doesn’t see that record as a coincidence
He added: ‘It comes down to the work we put in.
‘If you train well then nine times out of 10 you have a good performance on a Saturday. Long that may that continue!’