Taylor's ninth of the season was a typical long-range effort by the left-sided midfielder and added to Benjani's opener to ensure Portsmouth recorded their first ever victory over the Magpies in the Premiership.
Newcastle clawed one back in the second half with an Emre penalty but their first-half performance verged on the atrocious.
Roeder received more bad news when Damien Duff limped off ten minutes from time with what looked to be a bad knee injury.
The game started, somewhat surprisingly, the way of Newcastle as defender Craig Moore was guilty of a glaring miss after finding himself in yards of space at the far post.
Moore was left to rue his miss five minutes later when Benjani ended a four-month goal drought by firing home from 12 yards after out-muscling Steven Taylor.
Pompey piled on the pressure and went close to grabbing a second when Kanu's scintillating drive cannoned off the crossbar but didn't cross the line.
Roeder was forced into a rethink and hauled off the hapless Moore after just 30 minutes emphasising Newcastle's deficiencies in defence.
Just before the break they nearly grabbed an unlikely equaliser when Taylor's close-range toe-poke was cleared off the line by Lauren.
The lively Obafemi Martins seemed the only likely route to goal for Newcastle and, minutes after the break, the Nigerian was denied spectacularly by David James, who tipped his header over the bar.
England contender Taylor appeared to put the result beyond doubt when his sweet drive from 25 yards nestled in Steve Harper's far corner but Pompey captain Dejan Stefanovic ensured a tense final 25 minutes for the Fratton Park faithful.
He clipped James Milner's heels after the midfielder had danced inside him allowing Emre to convert from the spot.
The Turkey international's goal denied James the chance once more of breaking David Seaman's clean sheet record.
However, James turned hero once more at the death saving well from Martins to guarantee Pompey stay firmly in the hunt for a UEFA Cup qualification place.