LISBON, Jan 21 (Reuters) - An own-goal gave Porto a 1-0 win over lowly Naval in the Premier League on Saturday to maintain their three-point lead over champions Benfica.
After 19 matches Porto have 43 points ahead of champions Benfica, who beat Gil Vicente 3-1 away on Friday.
Nacional Madeira and Braga lead the chasing pack with 36 points after playing out 0-0 draws with Penafiel on Thursday and Academica on Saturday respectively.
Porto grabbed their victory with a goal after 30 minutes when a cross from the right by winger Ricardo Quaresma hit Naval Brazilian defender Fernando and the ball rebounded into his own net.
Benfica had to come from a goal down on Friday to beat Gil Vicente for their seventh league win in a row.
The home side went ahead with a penalty from midfielder Nandinho after nine minutes following a foul by Benfica captain Simao Sabrosa on Carlitos.
Sabrosa redeemed himself with the equaliser eight minutes later from the penalty spot after handball by defender Gregory.
Brazilian winger Geovanni put the visitors ahead when he tapped in a cross from the right by striker Nuno Gomes after 34 minutes.
Benfica made sure of the points thanks to Gil Vicente keeper Jorge Batista who scored an own-goal when he failed to clear a back pass from team mate Marcos Antonio after 55 minutes.