Winger Ciel was the star for Al Ahli in their comfortable 3-1 triumph over Al Nasr at Al-Rashid Stadium.
The 31-year-old opened the scoring after 20 minutes, before adding a second from the penalty spot five minutes before half-time.
Mahmoud Khamis halved the deficit shortly before the break, but Ciel provided the assist for Grafite to restore the two-goal cushion and wrap up the points for Cosmin Olaroiu's men shortly after the hour mark.
Al Shabab were hoping to stay within three points of the leaders, but fell to a 1-0 loss at title rivals Al Jazira on Friday.
In a tight match, it was the hosts who found the breakthrough in first-half stoppage time from Hyung-Min Shin, meaning Al Jazira overtake their opponents in the standings.
At the other end of the table, Ajman's dismal season continued in a 2-1 setback at fourth-placed Al Sharjah.
The damage was done in the first half with Fellype Gabriel and Ze Carlos opening up a comfortable lead for the hosts at the Al-Sharjah stadium.
Ismail Mohammed Al Jasmi pulled a goal back for Abdul Alwab Abdulkadir's men in the 79th minute, but the visitors could not find the equaliser despite Ze Carlos receiving his marching orders in the closing stages.
Dubai too are mired in relegation trouble, and they suffered a comprehensive 4-0 defeat at Bani Yas on Thursday.
The visitors had held their own in the first half at the Bani Yas Stadium, but four goals in the space of 15 second-half minutes did the damage.
Mohammed Fawzi and Ahmed Malalla scored with the space of three minutes shortly after the hour, before Ahmed Mallah was sent off for the visitors in the 77th minute.
Dubai's misery was compounded when a Haboush Saleh Habou double secured the comfortable win.
Al Shaab remain just one point outside the relegation zone following a 1-0 defeat at Wasl, with Mohamed Naser grabbing an 87th-minute winner.
Elsewhere, Emirates eased their own struggles with a 2-1 triumph over Al Wahda, while Al Ain and Al Dhafra played out a 1-1 draw.
