Paul Cook struggled to accommodate the youngster’s irresistible scoring talents into his League Two title winners.
In the setting of Westleigh Park, the challenge has now been hurled down to the new man at the Fratton Park helm.
A calf problem had kept Chaplin out of the pre-season opener at Salisbury, ensuring Saturday’s Hawks encounter was a first outing under Kenny Jackett.
The result was a 15-minute hat-trick and an assist in an impressive 6-0 victory over Lee Bradbury’s side.
The 20-year-old’s sparkling presence spanned 57 minutes, an intoxicating demonstration of his unquestionable finishing powers.
Irrespective of arriving against National League South opposition in a lone striking role, this was Chaplin at his most glorious.
In the ongoing bid to graduate from serial first-team substitute, the Academy product delivered an alluring message to the watching Jackett.
There are sufficient doubts whether Chaplin can remain as effective while operating in the 4-2-3-1 system which reaped promotion and silverware last season.
Pompey’s new boss must agonise over the extent of the youngster’s involvement in the forthcoming campaign – and if to implement an alternative system to find a way for regular inclusion.
The Blues already clutched a 1-0 advantage through Lee Molyneaux’s own goal and had hit the woodwork twice through Kyle Bennett when Chaplin struck for the first time.
On 30 minutes, recent recruit Tareiq Holmes-Dennis drove down the left flank and delivered a magnificent cross to the far post which was tapped home.
Then nine minutes later, a ball was knocked down the right flank, collected by the striker.
He drifted inside, teasing the covering Molyneaux, before driving a left-footed finish inside the near post from the most marginal of gaps.
Finally, in first-half stoppage time, Naismith cut the ball back from the left-hand side of the box, met with an instinctive first-time left-foot finish into the far bottom corner for the hat-trick.
The last goal was representative of a player inspired by confidence, a wonderful clean strike from just outside the penalty area which left keeper Ryan Young with no chance.
Yet Chaplin wasn’t done and on 47 minutes found space on the left to arrow a cross to the far post, where Naismith ghosted in to tap home the fifth of the game.
As the inevitable cascade of substitutes occurred during the second half, Chaplin made way for Milan Lalkovic on 57 minutes, much to the Hawks’ relief.
There was still time for substitute Curtis Main to win a 74th minute penalty following a slide challenge from Alfy Whittingham.
Main stepped up to finish left-footed to seal the 6-0 victory in front of a 2,700 Westleigh Park crowd – but it was Chaplin whose name was on everyone’s lips.
Hawks: Young (72 mins Walker-Harris), Woodford, Molyneaux (64 mins Wakley), Harris, Tarbuck, Lewis (64 mins Whittingham), Carter (64 mins Stock (79 mins Yoshida)), Fogden (64 mins Ridge), Williams, Prior (46 mins Odubade), Rutherford (46 mins Hayter). Sub not used: Robinson.
Pompey: Bass, Evans (72 mins Talbot), Burgess (72 mins Whatmough), Clarke (16 mins Davies), Holmes-Dennis (46 mins Haunstrup), May (76 mins Roberts), Rose (57 mins Close), Baker (57 mins Lowe), Naismith (72 mins Kabamba), Bennett (72 mins Main), Chaplin (57 mins Lalkovic). Sub Not Used: Collins. Attendance: 2,700.