The hosts had to wait until the 52nd minute to break the deadlock, with Junya Tanaka the man on target.
On-loan Manchester United winger Nani then rifled home a sumptuous second from long range to seal victory.
Sporting are third in the table, nine points behind leaders Benfica and two shy of second-placed Porto – who have a game in hand.
Belenenses boosted their UEFA Europa League prospects with a last-gasp 2-1 win at Maritimo.
Abel Camara's 26th-minute opener was cancelled out four minutes later by Edgar Costa, leaving Pele to steal the points with a last-minute penalty.
Academica and Arouca lifted themselves out of the relegation zone by winning 2-1 at Estoril and 1-0 over Rio Ave respectively.
Marinho secured an early breakthrough for Academica and a Rui Pedro penalty gave them breathing space before Leo Bonatini netted five minutes from time to set up a grandstand finish.
Agustin Vuletich was the match-winner for Arouca, while Yonathan Del Valle's red card forced Rio Ave to play the second half with 10 men.
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