Danny Cowley’s men fielded Bournemouth’s Christain Saydee up front to plug the gaping hole in their squad and the 20-year-old turned in an eye-catching display.
Nonetheless, there was plenty to be encouraged about over the display of powerful Saydee, who failed to net in 18 outings at Burton during the second half of last season.
He was one of five triallists on display for Danny Cowley’s men – albeit the only one to start the match.
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With 11 substitutions scheduled for the second half, after the break saw the introduction of ex-Ipswich defender Levi Andoh, Spurs keeper Josh Oluwayemi, former Middlesbrough striker Rumarn Burrell and ex-Liverpool and Derby right-back Andre Wisdom.
Although missing for the Blues were their only new signing Marlon Park, along with Michael Jacobs, Reeco Hackett and Denver Hume.
In the 12th minute, Ronan Curtis’ low cross from the left was met with a first-time shot from Marcus Harness from the edge of the six-yard box, but Joe Newton’s brilliant slide block thwarted a certain goal.
Triallist Saydee spang to life on 27 minutes with a powerful surge up from the pitch from the halfway line, which saw Joe Oastler’s attempted rugby tackle on him fail.
However, his subsequent cross from the right was easily cleared by the back-pedalling Hawks defence.
Then Harness teed him up with a delivery from the right, but, despite Saydee collecting the ball well, he was quickly closed down and unable to get a shot off.
The deadlock was broken on 34 minutes when Harness laid the ball down the right to pick up Tunnicliffe’s clever run into the box.
The midfielder shaped to cross, yet instead fired in a near-post shot which took a deflection and found its way into the net.
Pompey extended their lead on 40 minutes when a tremendous deep cross was swung in from the right by Harness.
Curtis challenged at the far post, yet Passley could only bundle the ball into his own net as he attempted to outmuscle the Blues winger.
Saydee had impressively grown into the game and he finished the half outmuscling Billy Clifford off the ball to steal it and then sending a 40-yard lob just over the bar.
Cowley made 11 substitutes at the break and on 48 minutes the scoreline became 3-0.
Vincent, on at left-back for Connor Ogilvie, rifled in a left-footed free-kick from 25-yards for a stunning Blues third.
The visitors should have extended their lead on 70 minutes following a lovely move which saw Harry Jewitt-White unselfishly square to Rumarn Burrell, but his shot was saved.
There would be no further change to the scoreline as Cowley’s men claimed a 3-0 success in their first pre-season outing.
Pompey (1st half): Bass, Freeman, Raggett, Robertson, Ogilvie, Morrell, Thompson, Tunnicliffe, Harness, Saydee, Curtis.
Pompey (2nd half): Oluwayemi, Andoh, Mnoga, Wisdom, Vincent, Mingi, Jewitt-White, Burrell, Reid, Bridgman, Gifford.
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