Lech finished the 2021/2022 campaign five points ahead of Raków and nine points ahead of Pogoń Szczecin.
In the final round of matches, the Poznań club, managed by Maciej Skorża, won 2-1 against Zagłębie Lubin at home on Saturday, while Raków posted a comfortable 3-0 win against Lechia Gdańsk.
Lech Poznań manager Maciej Skorża. Photo: PAP/Jakub Kaczmarczyk
Meanwhile, top-flight powerhouse Wisła Kraków, managed by former Poland boss Jerzy Brzęczek and co-owned by national team ex-captain Jakub Błaszczykowski, finished the season second from the bottom and will be relegated from the Polish premier league.
Lech had secured its eighth Polish Ekstraklasa championship after Raków lost 0-1 to Zagłębie Lubin the previous weekend.
Earlier this month, Raków beat Lech 3-1 to win the Polish Cup.
The two teams will face off against each other for the national Super Cup title later this year in a curtain-raiser to the next football season.
Lech and Raków will also represent Poland in European competitions, which are due to begin later this year. Joining them will be Pogoń Szczecin, who finished third in the Polish premier league, and fourth-place finishers Lechia Gdańsk.
Source: TVP Sport, Canal+, IAR, PAP