Coventry City's five-game winning streak away from home was brought to an end at a chilly Fratton Park as League One strugglers Portsmouth handed Steven Pressley his first defeat as Sky Blues manager.
Gary McSheffrey spurned a chance to put City ahead after five minutes when his penalty was saved by Simon Eastwood and Jed Wallace compounded the frustration when he put Pompey ahead after 14 minutes.
Patrick Agyemang then grabbed a second for the home side on 76 minutes to hand City their first away defeat since the middle of January.
Pressley rung one enforced change to his starting lineup for the clash with Pompey, bringing in John Fleck for the injured Carl Baker to hand the Scot his first start since
It was striker Cody McDonald who handed the Sky Blues a glaring opportunity to take the lead after just five minutes though when he ran onto a through ball from McSheffrey before being tripped in the area by Shaun Cooper.
It was McSheffrey who was elected to take the spot kick though, the midfielder sending the ball to Pompey 'keeper Simon Eastwood's left only to see the shotstopper guess right and parry the ball away.
Despite City's encouraging start, however, it was Portsmouth who took the lead on 14 minutes through Wallace.
Some intricate one-touch passing down the touchline eventually brought the hosts into the City area where the ball was laid on for Wallace to lift a finish over the reach of Joe Murphy and just underneath the cross bar from 12 yards.
City continued to press forward though on a difficult surface and Franck Moussa was left disappointed for not working Eastwood harder with his effort from 20 yards after 25 minutes.
Cyrus Christie was also lively down the right flank and very near;y carved out a chance for himself a minute later when he chopped inside his marker but curled an effort across the face of goal and wide of the far post.
Gabor Gyepes then went close for Portsmouth just after the half hour when a corner delivery was only cleared as far as Gyepes who fired over the bar from a tight angle.
City started the second half brightly though when, just seconds after the restart, Christie got forward and cut in from the right and shot at goal from just outside the area, the ball moving in the air and almost deceiving Eastwood who had to push the effort away from danger.
Pompey had two bites at the cherry on 50 minutes though when a floated cross from Wallace found Liam Walker at the back post to shoot only for the shpt to be blocked by William Edjenguele with Johnny Ertl firing the follow up over the bar.
Aaron Martin took the Pompey 'keeper by surprise two minutes later when he fired a piledriver from more than 30 yards. It was too much for Eastwood to hang on to although Moussa's follow-up flashed across the face of goal and just wide of the far post.
Moussa went close again seven minutes after the hour when he was picked out by Martin, Moussa being forced wide before his effort was tipped over the bar by Eastwood.
City had another chance after the resulting corner though when Pompey failed to clear John Fleck's delivery which eventually fell to the feet of sub Callum Wilson whose effort was blocked for a corner by Walker.
It was the home side who got the second of the afternoon though to stretch their lead when, on 76 minutes, a cross swung in from Walker met the head of Patrick Agyemang who glanced the ball beyond the reach of Murphy and just inside the far post.
It was nearly three with three minutes to go when Agyemang broke away and squared a ball for David Connolly whose goalbound effort was beaten off the line by a scrambling Edjenguele.
City then almost clawed one back through substitute Callum Ball who poked a low cross from Moussa at goal only for Eastwood to be equal to it.
The Pompey 'keeper was at it again as the game headed into five minutes added time when Wilson came steaming through midfield and fired at goal only for Eastwood to parry away what was City's last chance of note.
Attendance: 12,601 (1,079 Sky Blue Army)
Coventry City: Murphy, Christie, Martin, Edjenguele, Stewart (Ball 79), Bailey, Jennings (c) (Wilson 64), Moussa, Fleck, McSheffrey (Thomas 64), McDonald
Subs: Dunn (GK), J Clarke, Bell, Willis
Portsmouth: Eastwood, Cooper, Walker (Maloney 90), Connolly, Moutaouakil, Gyepes, Ertl (c), Racon, Agyemang (Akinde 90), Rocha, Wallace
Subs: Smith (GK0< Sodje, Harris, Webster, Butler
Referee: P Gibbs
Assistant Referees: K Johnson, M Scholes
Fourth Official: G Muge