Forward Adolfo Bautista put the Chivas ahead in the 27th minute of Saturday's match and defender Hector Reynoso secured the victory in the 86th after San Luis goalkeeper Adrian Martinez had saved a Javier Hernandez penalty.
The record, however, is beginning to weigh heavily on Guadalajara who were lucky to win against a San Luis side who controlled long spells of the match.
Guadalajara lead Group One of the Clausura championship with a maximum 24 points, 10 more than second-placed Queretaro after eight matches. The Chivas are five points ahead of champions Monterrey in the overall standings.
Monterrey, who won 1-0 away to Atlante, head Group Two by three points from Morelia and Santos Laguna, held 1-1 at Queretaro, are two points ahead of Pumas UNAM at the top of Group Three.
The top two in each of the three groups plus the next two best-placed teams overall qualify for the knockout phase of the championship.
Cruz Azul, recovering from a poor start to the year, beat Atlas 3-1 at home with two goals from centre-back Melvin Brown and one by Argentine striker Emanuel Villa, his first goal of the Clausura.
Villa, the Apertura championship's leading scorer in the first half of the season averaging more than a goal a game when Cruz Azul finished runners-up to Monterrey, had not scored since November.
Atlas had their Argentine midfielder Dario Botinelli sent off nine minutes from time for a second booking.
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