The result took the hosts to second place, as they have a superior goal difference over third-placed KCCA. Each of the pair has 45 points.
Vipers SC skipper Milton Karisa produced the decisive moment in a hotly contested Uganda Premier League encounter against KCCA FC on Friday.
Under the floodlights at the St Mary's Stadium, Kitende, the Venoms stole the victory in the latter stages of the match, having witnessed a host of chances from both sides go begging.
The result took the hosts to second place, as they have a superior goal difference over third-placed KCCA. Each of the pair has 45 points.
With Vipers playing a game fewer than KCCA and two less than leaders SC Villa who have 46 points, the Venoms are looking strong to defend the title.
In the evening, it was tense, yet evenly poised as both sides had chances to report home in both halves.
The hosts, in the opening half, had an early chance to break the deadlock, but Karisa and Abubaker Lawal failed to tuck the ball in after just two minutes.
Rogers Mato then had a decent chance to give KCCA the lead in the 30th minute, but his shot from outside the box missed the target by inches.
Allan Okello thought he had put the guests in front in the 68th minute, but his curling shot hit the woodwork, as Mato's follow-up went acres over the bar.
The Venoms also missed two glorious chances in quick succession as both Martin Kizza and Cromwell Rwothomio were denied by the away backline.
However, in the 88th minute, Karisa wasn't to be denied as shot with his weaker foot, and the ball evaded the defense to steal it for the home team.
Vipers will hope to make it to the top when they visit Soltilo Bright Stars FC in their next match at the Kavumba Recreation Grounds on Tuesday.
Meanwhile, KCCA will hope for a quick turnaround when they visit rivals Express FC on May 13 in a Kampala derby.
How they lined up
Vipers: Fabien Mutombora (GK), Ashraf Mandela, Hilary Mukundane, Rogers Torach, Isa Mubiru, Siraje Ssentamu, Nzau Lutumba, Abubakar Lawal, Milton Karisa (c), Karim Ndugwa, Martin Kizza
Substitutions: Denis Kiggundu, Karim Watambala, Abdu Lumala, Cromwel Rwothomio, Disan Ggaliwango, Bright Anukani
KCCA: Benjamin Ochan (GK/C/), Filbert Obenchan, Mustapha Kizza, Mustafa Mujuzi, Geofrey Wasswa, Saidi Mayanja, Simon Tshisungu Kankonde, Moses Waiswa, Allan Okello, Rogers Mato, Denis Iguma
Substitutions: Derrick Ochan, Peter Magambo, Julius Poloto, Muhammad Shaban, Hassan Mubiru, Charles Lwanga, Ashraf Mugume