LISBON, Dec 11 (Reuters) - Champions Porto stayed five points clear at the top of the Portuguese Premier League with a last-goal gasp to beat Nacional 2-1 away on Monday.

Porto, who came from a goal down to earn the deserved victory, top the standings with 34 points from 13 matches, ahead of Sporting who beat Vitoria Setubal 3-0 on Saturday.

Benfica who drew 0-0 with promoted Naval on Sunday are fourth, level on 23 points with third-placed Braga who lost 2-0 to Belenenses on Friday. Benfica have a match in hand.

Nacional went ahead after 13 minutes through Jose Vitor who tapped in a cross from Juliano on the left.

Brazilian striker Bruno Moraes equalised for Porto after 75 minutes after a neat cross from the left by winger Ricardo Quaresma.

With one minute to go, Argentina midfielder Lucho Gonzalez grabbed the winner.