Asamoah Gyan and Omar Abdulrahman both scored twice to help the visitors earn their seventh win in nine games.
Gyan opened the scoring after four minutes and Alex Brosque made it two on the quarter-hour mark.
Brosque then put through his own net, but Abdulrahman made it 3-1 in the 33rd minute and added another 10 minutes later.
Gyan got his second from the spot in the 67th minute before Richard Porta got another consolation for Dubai late on.
Second-placed Al-Nasr were 3-1 winners at home to Dibba Al Fujairah.
Giuseppe Mascara put the hosts in front in the 11th minute, but Luiz Fernando levelled midway through the first half.
Al-Nasr responded, though, Bruno Cesar making it 2-1 in the 72nd minute and Humaid Abbas sealing the win eight minutes later.
Al-Ahly Dubai kept the pressure on the top two with a 6-2 away thrashing of Al Wahda.
Former Wolfsburg striker Grafite scored four times for the visitors, who led 3-1 at the break and whose other goals came from Luis Jimenez and Emana.
Papa Waigo and Issa Ahmed Santo were on target for Al Wahda.
In the day's other game Al-Sha'ab and Al-Dhafra drew 2-2.
Omer Aziz and Hassan Matouk with a penalty put Al-Sha'ab two up, but Makhete Diop and Amara Diane earned a point for the visitors.