The Wolves can ensure the title with a victory against reigning champions Al Duhail in the next match.
The win took Gharafa’s tally to 22 points while Arabi remained on 27.
Captain Rodrigo Tabata scored the winner for Al Rayyan who moved to third in the table.
Valentin Marius Lazar scored the winner as Al Kharaitiyat defeated Qatar Sports Club.
Ivory Coast striker Wilfried Bony now has four goals in three matches.
The result helps Duhail warm up well for Esteghlal clash.
Al Kharaitiyat drub Al Gharafa
Gharafa keeper Youssef Hassan made a string of late saves to deny Duhail.
Al Duhail take on Al Gharafa in another important fixture.
Valentin Marius Lazar’s goal helped Kharaitiyat register their second victory in the league.
Qatar SC held goalless by promoted side Al Shahania.
Reigning champions Al Duhail made the biggest changes during the winter transfer, bringing in new coach Rui Faria defender Medhi Benatia and forward Shoya Nakajima.
Nakajima was named last September's Primeira Liga player of the month following a run of outstanding performances with Portimonense.
Gharafa defeated reigning QSL champions 1-0 in a tough final on Thursday to retain their title.
Vladimir Weiss scored the winner as Gharafa beat Al Duhail SC in the final