Guikan was drafted into the squad in the last minute after first choice striker Jacques Tuyisenge pulled out of the match with an injury picked during the team's warm-up session.
But the Ivorian restored coach Dylan Kerr's faith in him with a first class display in the opening stanza that also saw K’Ogalo keep a clean sheet for the first time in six games.
Gor Mahia came into the match with the mentality of a true champion and coach Kerr knew that he needed to win this tie to bounce back from a draw against Sofapaka last time out.
Humphrey Mieno fired a shot on the face of Sony Sugar's goal in the 14th minute, but the former Tusker midfielder’s thunder-bolt missed the target by a few inches.
A tightly marked and unlucky Meddie Kagere’s appeal for a foul inside Sony Sugar’s box was turned down after K’Ogalo once again made a raid on the Millers dangerzone from the left flank, but Godfrey Walusimbi’s cross evaded everyone.
It was an evening punctuated by heroic saves from Sony Sugar goalkeeper Kevin Omondi and missed chances from Kagere.
Omondi, who produced a man of the match performance, made his maiden meaningful save of the day when he denied Guikan from an attempted bicycle kick but his heroic display could not save Sony from losing their eighth game of the season.
Omondi once again did well to save Sony from going down when he recovered to deny Kagere after the Rwandan cheekily headed George Odhiambo's cross from the left.
Sony sat too deep in their half and the approach worked against them with eight minutes left before the break. Francis Kahata, Innocent Wafula and Kagere all linked up in the build-up to set Guikan, who broke the ice in the 40th minute.
Sony came back into the second half with an open mind. Former Tusker man David Otunga beat his marker but his final delivery did not get to Clinton Omondi.
Gor Mahia responded to the attack with another dangerous run by Guikan, but Sony defence dealt with the cross. Sony custodian Omondi stood firm with a brave display after he parried a Kahata free-kick only to get off the ground to deny Guikan from the rebound.
Omondi was outstanding between the posts and Kagere will bear testament to that when the on-form keeper denied him once again from point blank with his double saves that also saw him parry the rebound to keep the slim lead by the visitors.
Gor Mahia now tops the log with 34 points while Sony remain bottom of the standings. Gor Mahia have conceded 14 times and scored 31 goals in the process, the highest by any club this season.
Sony Sugar XI: Kevin Omondi, Kevin Oluoch, Benard Omondi, Samuel Olare, Martin Werunga, Fredrick Onyango, Clement Owino, Festus Okiring, Tobias Omondi, Steve Otieno, Clinton Omondi and Derrick Otanga.
Subs: Salim Sowedi, Alfred Onyango, Joseph Omweri, Daniel Otieno, Moses Mwangi, Stephen Onyango and Dennis Junior.
Gor Mahia XI: Boniface Oluoch, Innocent Wafula, Godfrey Walusimbi, Haron Shakava, Joash Onyango, Humphrey Mieno, Ernest Wendo, Francis Kahata, George Odhiambo, Meddie Kagere and Jacques Tuyisenge (Ephrem Guikan).
Subs: Shaban Odhoji, Wesley Onguso, Philemon Otieno, Lawrence Juma, Boniface Omondi and Cercidy Okeyo.