Former Southampton striker Davies pounced on 53 minutes when he diverted Nicky Hunt's right wing cross past the Pompey goalkeeper Shaka Hislop who saw the ball squirm under his body. The South Coast club suffered a double dose of misery when Dejan Stefanovic was dismissed in the final minute for a clash with referee Phil Dowd.
Those where the highlights of what was, on the whole, a poor game which was very scrappy under difficult conditions. Bolton manager Sam Allardyce gave recent signing Javi Moreno his first start in the team at the expense of Per Frandsen whilst Anthony Barness also filled in for hamstring victim Simon Charlton who was on the bench.
The first half was a very poor contest with neither side really creating anything clear cut, the opening half of the game was all about possession and neither side could break their opponents down.
Bolton midfielder Ivan Campo had the first clear shot of the game just after the half hour mark when his drive from the end of the area stung the fingertips of the Pompey keeper Hislop, but the former Newcastle and West Ham stopper was quick to lap up the rebound to stop Youri Djorkaeff from giving the home side the lead.
Anthony Barness, recalled after just one day into a loan spell with West Ham United also tested Hislop but his low shot from 18-yards wasn't enough to give Bolton the lead.
The second half was much better, both teams showed that bit more urgency and passes where coming together, the improvement in the play showed when Hislop made the first of two fine saves to deny former French World Cup winner Youri Djorkaeff shortly after the break.
Then a couple of minutes later the Bolton striker Davies found himself through on goal but he was unable to get his shot on target. However the 26-year old made amends on 52 minutes when he gave Bolton the lead. Youri Djorkaeff played a cute pass to the Wanderers full back Nicky Hunt and his square ball was poked home by Davies past the despairing Hislop to give the Trotters the lead.
Portsmouth almost responded immediatly when Nigerian striker Yukubu Aiyegbeni hit the post after the Bolton defence had failed to clear and this seemed to bring Harry Redknapp's team back to life.
On 58 minutes Pompey midfielder Richard Hughes was booked for a foul on his Bolton counterpart Ivan Campo which lead to both team captains Bolton's Jay-Jay Okocha and Portsmouth's Teddy Sheringham having to be spoken to by the referee Phil Dowd, amazingly Okocha was booked for his protests whilst Sheringham got away with a word of warning.
Youri Djorkaeff then forced a second fine save out of Shaka Hislop when he arrived at the far post but the giant stopper turned the ball away to avert any danger.
On 75 minutes on loan Chelsea midfielder Alexei Smertin went close for the South Coast outfit when he saw his 18-yard drive turned away for a corner by the Bolton keeper Jussi Jaaskelainen as the away side went in desperate search for an equalising goal.
Patrik Berger then had a chance a few minutes from the end to level the scoring but the former Liverpool midfielder volleyed wide of Jaaskelainen's post to cap off what was a miserable day for the Fratton Park club who will look back at the game and regret not being as clinical as they where when the two sides met in September.
Their misery was complete when defender Dejan Stefanovic was sent off for arguing with referee Dowd after Kevin Davies had gone on the counter attack for Bolton. The game still means that Pompey's dismal record in Bolton continues and hasn't helped their chances of moving away from the drop zone whilst Sam Allardyce's team move into 10th spot due to their win today.