The Brazilian scored his first from penalty the spot nine minutes before half-time and put daylight between the sides two minutes after the restart.
Asamoah Gyan, the league's top scorer, gave Al Ain hope with a spot-kick of his own with 12 minutes remaining but Ahmed Khalil scored a third for the visitors in injury time.
And despite Ismail Ahmed responding again for the hosts, it was not enough to deny Al Ahli a fifth win in a row in the league.
Despite having Mahmood Qassim sent off just before half-time when he received a straight red card, Al Shabab's 10 men fought on and won it early in the second thanks to an Edgar Silva strike - the club's fourth successive 1-0 win in the league.
Walter Zenga's side looked well on course for victory after racing into a 3-0 lead inside 43 minutes thanks to an Ahmed Al Ghilani brace either side of a penalty from Abdelaziz Barrada.
Ismaeil Matar and Eisa Ahmed struck after half-time to reduce the deficit but when former Manchester City striker Felipe Caicedo grabbed a fourth after 69 minutes and Al Wahda's Adel Basulaiman was sent off for a second booking two minutes later, the game looked over.
And despite Ahmed Jumaa's reply four minutes later, the home side held on to claim a fourth win of the season, which moves them up a place into 11th, while condemning Al Shaab to a fourth defeat in five league games.
Emirates dropped below Ajman after losing 2-1 at Bani Yas on Sunday. Salim Al Ali opened the scoring and although the visitors equalised courtesy of Gustavo Herrera's 27th minute penalty, Bani Yas won it with a second-half Nawaf Mubarak Musabh effort.
