A run of seven games without a win has seen Miguel Cardoso's side drop to 15th spot in the Primeira Liga table, just two points above Maritimo in the relegation playoff place, while the visitors recently dragged themselves out of immediate danger and up to 11th place.
Portimonense picked up a somewhat disappointing result last time out, as they played out a 1-1 draw away at 17th-placed Farense.
Before that, they suffered a disappointing 5-1 home defeat to Benfica.
Portimonense took the lead in the 43rd minute through Beto, but the lead would not last long as Pizzi equalised on the stroke of half time before Darwin Nunez and Everton found the net alongside a Haris Seferovic brace.
Despite their poor recent run, Paulo Sergio's side did manage to drag themselves away from the bottom three with a run of three consecutive victories at the beginning of April.
Portimonense now sit in 11th spot in the top flight, five points ahead of Boavista in the relegation playoff place and seven points above the automatic drop zone.
As a result, they will feel that one more win in the final five games of the season should confirm their safety.
They take on a Rio Ave side who are much more involved in the fight for survival, having failed to win any of their last seven league games.
Miguel Cardoso's side picked up a point last time out, as Fabio Coentrao netted an equaliser soon into the second half to seal a 1-1 draw at home to Pacos de Ferreira.
While that does not seem a disappointing result on the surface, it did put an end to Pacos de Ferreira's four-game losing run, while stretching Rio Ave's winless run to seven matches.
In that time, Os Rioavistas have picked up just five points, while also suffering defeats to fellow strugglers Maritimo and Gil Vicente.
As a result, they have quickly fallen down the table, now sitting just one place and two points ahead of Boavista in the relegation playoff spot, and four points above the automatic drop zone.
That means Rio Ave quickly need to turn their form around if they are to remain out of the bottom three, with 15 points left to play for for the sides in the drop zone.
The Portimonense attack will be led by Beto, who has recorded 11 goals and three assists in 25 appearances in the Portuguese top flight this season.
He will be supported by Aylton Boa Morte, who netted his fifth league goal of the season to equalise against Farense last time out.
Rio Ave will come into this game without experienced right-back Ivo Pinto, who will serve a suspension after he was sent off in the recent draw with Pacos de Ferreira.
Winger Carlos Mane could also be out of Saturday's clash, after he was absent from the squad in the latest game.
Former Real Madrid left-back Fabio Coentrao operated as a right-winger last time out, and he could continue in that new role after netting the equaliser to seal a point for his side.
They have struggled to find goals elsewhere this season, with frontman Gelson Dala netting just three goals in 26 Primeira Liga appearances.
Portimonense possible starting lineup:
Samuel; Moufi, Possignolo, Antonio, Cande; Clemente, Rocha, Ewerton; Boa Morte, Beto, Fabricio
Rio Ave possible starting lineup:
Kieszek; Costinha, Borevkovic, Santos, Amaral; Tarantini, Augusto; Coentrao, Guga, Geraldes; Dala
We say: Portimonense 1-1 Rio Ave
Neither side come into this game in inspiring form, and we do not see either outclassing the other on Saturday.
While Rio Ave require a win to put a gap between themselves and the drop zone, they look devoid of confidence and could see their winless run stretched to eight games.