Barcelona coach Ernesto Valverde promised no let up from his side despite them going 11 points clear at the top of La Liga.
before nearest challengers Atletico Madrid slipped up 2-1 at Villarreal.
Despite his side being on the brink of a third title in four seasons, Valverde warned they would not be taking their foot off the gas.
We only have 27 points left [to play for] and we will try and win them all, he told the club`s official website. Carrying on like this will help us reach our objective.
Lionel Messi scored for the sixth consecutive game, taking his tally for the season to 38 in all competitions with a fine finish from the edge of the penalty area after half an hour.
Paco Alcacer had already given the hosts the lead at the Nou Camp, and the leaders went on to canter to a routine victory against a Bilbao side grateful they were not more soundly beaten.
We dominated in the first half and created lots of goalscoring opportunities: we were brilliant. In the second half, we were solid, added Valverde. The team and the players are showing that we attack and defend all together.
Alcacer made the most of a rare start for Barca in the absence of suspended striker Luis Suarez.
After scoring only his third league goal of the season, he said: I try to go out on the field and play to help the team and if I can with goals.
We knew that Athletic would defend well and how we had to approach the game. The mentality that we have is to win and not to look at the table. We focus on the present and not the future