Porto must continue to capitalise on the poor form of league leaders Sporting Lisbon when they travel to play Nacional on Friday at Estadio da Madeira in their 17th Primeira Liga game of the season.

preview

The hosts and Rio Ave both produced three big chances in their clash last Sunday, but the latter created 2.05 xG, considerably more than Nacional's figure of 0.63 xG.

The defeat means that Nacional occupy the league's relegation playoff spot and are only one point ahead of the two automatic relegation spots at the bottom of the division, but they are level on points, goal difference, goals scored and goals conceded with 15th-placed Farense.

Manager Tiago Margarido will be concerned that his team's return of 11 goals scored in the top flight only betters the numbers posted by two clubs, though his side's record of 23 goals conceded is the league's joint ninth-best tally.

The Nationalists are in poor form having lost four, drawn two and won just two of their eight most recent outings, and they have in fact been defeated in nine of their past 14 games.

Margarido's side have at least proven difficult to beat at home, with the club winning three and drawing one of their seven matches at Estadio da Madeira, and it should be noted that two of their three defeats have come against giants Sporting Lisbon and Benfica.

Opponents Porto thoroughly outclassed Boavista on Saturday given they produced seven big chances while preventing their opponents from creating a single one themselves.

Head coach Vitor Bruno will be delighted that his side have so far managed to take advantage of the fact Sporting have dropped eight points in their last five league matches, with his team picking up 13 points in that time.

The Dragons have been outstanding at both ends of the pitch, with the title hopefuls scoring 40 goals and conceding just nine times in the league, and these are the top flight's second-best offensive and joint best defensive records.

While the visitors have only failed to win three of their last seven away matches in the league, they have lost three, drawn two and triumphed in just one of their six most recent games on the road in all competitions.

Porto's record against Friday's hosts is impressive considering they have emerged victorious in 18 of their 22 clashes, with Nacional's last win coming in March 2014.

Nacional possible starting lineup:

Encarnacao; Garcia, Ulisses, Santos, Gomes; Soumare, Esteves; Aurelio, Costa, Dudu; Isaac

Porto possible starting lineup:

Costa; Fernandes, Perez, Otavio, Galeno; Sousa, Eustaquio; Vieira, Mora, Pepe; Aghehowa