Vihiga, who are leading the lower league, came into the match with clear intent and it took them only 14 minutes to force keeper Duncan Ochieng’ to a save to keep the score board clean.
The County government sponsored side, however, could not pull their foot off the gas when Okwemba converted from the spot in the 24th minute after Tusker committed a foul inside their box.
Tusker were dented a blow after Cercidy Okeyo was pulled out with an injury. He was replaced by the club’s reigning player of the month, Jackson Macharia but even his presence in the midfield that also had Humphrey Mieno, could not dwarf Okwemba’s tricks.
But Tusker threw in the entire arsenal in search of an equalizer, with Anthony Ndolo being pulled out for Michael Khamati but it was the minnows, who had the last laugh when Lugalia banged in a second goal an 87th minute.
The win could not have come at a better time for Vihiga, who lost their coach, Edward Manoah after he was sent to the stands with 15 minutes to play.
Tusker starting XI: Ochieng Duncan, Tangauzi Marlon, Mwangi David, Asike Eugine Asike, Situma James, Okeyo Cercidy, Danson Kago, Mieno Humphrey, Owusu Stephen, Ndolo Anthony and Muchiri Boniface.
Subs: Okello David, Wahome Lloyd, Osumba Brian, Alwanga Clifford, Odhiambo Paul, Macharia Jackson and Ndinya Victor.
Vihiga United: Frank Mwenda, Edwin Mukoya, Dennis Ombeva, Liuva Mophat, Ochieng' Bernard, Soita Silicho, Christopher Masinza, Okulo Patrick (c), Rashid kyambadde, Charles Okwemba and Dennis Wafula.
Subs: Caleb Wamalwa, David Kavaji, Kevin Muhanji, Airo Godfrey, Clyde Senaji, Dennis Lugalia and Oscar Omwami.