Pompey were denied a third away win of the season after Charlie Wyke's strike in the fifth minute of stoppage time robbed Andy Awford's men of all three points.
As if the Portsmouth fans weren't getting fed up with this season as it is, this cruel end to a match which the visitors dominated for long periods will only deepen the irritation as the season peters out to its disappointing conclusion.
Kyle Dempsey put the Cumbrians ahead after just two minutes with a volley from the edge of the box as Pompey were all at sea for the first twenty minutes of the game.
However, a new look side deployed in a 4-2-3-1 formation soon began to take control of the match and Jed Wallace equalised with an excellent strike from 35 yards.
Jed was the outstanding performer on the day and he played his part in the second goal by producing a brilliant cross for Matt Tubbs to tap in from all of a yard out just before the break.
The Pompey defence needed patching up early in the second half as Nyron Nosworthy replaced Ben Chorley only to go off with a head injury early on with Adam Webster taking his place.
Wallace and Tubbs had other chances to score whilst Ryan Taylor had a goal rightly ruled out for offside after the goalkeeper could only parry James Dunne's strike into his path.
Fans from both teams who were at the game accept that Pompey were the better side and were cruising as the match drifted to its conclusion, but then came the suckerpunch right at the death as the ball fell for Wyke in the box who slotted home.
It's a frustrating result which has angered Pompey fans as they have failed to beat a really poor side despite the performance, although much of that was down to Wallace whose stock continues to rise.
Fears that he is certain to leave in the summer might want to read this interview with The News as it's very insightful. If he ends up being sold, it makes you wonder how Pompey will fare without him next season as he'll be difficult to replace.
Today's draw leaves Pompey in 14th place ahead of a difficult game with Plymouth on Easter Monday. Should Awford's team not improve on that position, he may find himself out of a job come the summer, which would be hugely disappointing for such a popular figure at the club.