The Ruaraka-based side are now on 26 points after 11 games, four more than second-placed KCB
Jackson Macharia scored the lone goal in the stoppages to help Tusker defeat Wazito FC 1-0 at Kasarani Annex on Friday in a Football Kenya Federation Premier League assignment.
Both teams had come into the match desperate for maximum points to go top of the table.
It was the visitors who started the game on a high hoping to get an early goal and in the 12th minute, Emery Mvuyekure was forced into a fine save to deny Fidel Origa and a minute later, it was Musa Masika who tried his luck but missed the target.
In the 22nd minute, once again, it was Wazito who had a chance to get a goal when they won a free-kick in a good area, but Kevin Kimani sky-rocketed his effort.
The 11-time champions had to wait until the 35th minute to get their first shot on target. Wazito conceded a free-kick about 30-yards from their goal and Ugandan Hashim Sempala took it, but goalkeeper Levis Opiyo deflected the ball for an unfruitful corner.
With three minutes to the break, the Ruaraka-based charges were forced into making a change. Eugene Asike hurt his groin and Vincent Ngesa took his place.
Tusker came back stronger in the second half and in the 53rd minute, they had a good chance from youngster Henry Meja. He managed to work his way into the danger zone but his strike missed the target by inches.
Seven minutes later, the forward, once again, had a massive opportunity to score. But he was denied by the crossbar after doing everything right.
Francis Kimanzi introduced his new signings Elli Asieche and Erick Otieno to try and get a goal, but they could not get a chance owing to good defending by their hosts.
With 15 minutes to go, veteran midfielder Humphrey Mieno had a chance to get his shot on target and maybe get a goal for his team but shot over from 20-yards out.
It seemed spoils will be shared until Macharia scored a stunning goal with seconds to the final whistle after getting a chance in a good area owing to concentration lapse by the visitors.
The Ruaraka-based side are now on 26 points after 11 games, four more than second-placed KCB. Wazito are third with 20.
Tusker XI: Mvuyekure Emery, Monyi Kevin, Wandera Hillary, Oruchum Christopher, Asike Eugene, Sempala Hashim, Namanda Luke, Otieno Apollo, Meja Henry, Macharia Jackson, Muchiri Boniface
Subs: Wanjala Michael, Ngesa Vincent, Mbugua Jimmy, Odenyi Faraj, Mieno Humphrey, Ogutu George, Zakayo Eric, Majak David.
Wazito XI: Opiyo Levis, Sikhai Dennis, Ng'ang'a Dennis, Ochieng' Benard, Omurwa Johnstone, Origa Fidel, Isuza Whyvonne, Kimani Kevin, Omondi Boniface, Masika Musa, Owino Michael
Subs: Odhiambo Fredrick, Otieno David, Odhiambo John, Asieche Elli, Oburu Vincent, Musa Brian, Asembeka Amos, Maurice Ojwang'