Sporting Lisbon was restricted to a third draw in four Primeira Liga outings this term against Belenenses.
The visitor took a 28th-minute lead at the Estadio Jose Alvalade through Brazilian striker Deyverson.
Sporting's Peruvian attacker Andre Carrillo levelled matters six minutes later but that was as good as it got for the host.
Belenenses lies sixth - a point better off than Sporting, which had defender Jefferson sent off in stoppage time for a second bookable offence.
Rio Ave edged back ahead of Benfica at the top of the standings but lost its 100 per cent record as it was held to a draw at Moreirense.
Diego Lopes broke the deadlock for the away side with 28 minutes played but Moreirense - which now has five points from four outings - enjoyed an ideal start to the second period as Vitor Gomes restored parity.
Vitoria Guimaraes hosts Porto on Monday (AEST) and if there is a winner in that game Rio Ave will be dislodged.
Arouca picked up the first win of the campaign and was Sunday's only winner as Claro's fifth-minute opener proved enough to secure a surprise 1-0 triumph over Sporting Braga.