Bolton boss Phil Parkinson urged supporters to stop their protests against the club's owner and get behind the team after the Trotters lost 2-0 at home to West Brom.
Some fans staged a demonstration outside the University of Bolton Stadium before the game and kick-off was briefly delayed after tennis balls were thrown on to the pitch in protest at owner Ken Anderson's running of the troubled side.
Wanderers, who are second-bottom in the Championship and three points from safety, were undone by goals from Jay Rodriguez and Sam Field against promotion-chasing Albion.
And Parkinson says the club needs to be united if they are to beat the drop.
Parkinson said: "We knew that there was going to be a protest prior to the game and maybe problems as the game went on, but we stressed to the lads to focus and I felt we did that, we concentrated on what we had to do, we gave it everything.
"I think with the supporters, they know that these last blocks of games are as important as the club has had in its recent history, and they have done what they wanted to do, now it is up to the supporters to get behind the team and help us in our quest to stay in the league.
"In the first half I thought we were the better side, we restricted them to very little, and one moment has taken us in to half-time 1-0 down, and I didn't think we deserved that.
"I thought we did well, a lot of good things tonight, we have come up against a team with a lot of quality and I thought we were right in the game."
Albion led after 19 minutes when Chris Brunt's free-kick from the left found its way to the back post, where former Trotters loanee Craig Dawson headed across goal for Rodriguez to nod in from on the line.
Substitute Field added a second for Darren Moore's Baggies, running on to a through ball to guide his shot past Ben Alnwick with 15 minutes left.
Moore said: "We had to focus on the game tonight, and we got the result irrespective of the pressure of the game, there was only a clear focus in my mind.
"We knew the protests would happen at any point in the game, and for me as a head coach it was just about maintaining the focus on the pitch along with the players because you can get easily distracted, but we've just come up here as West Brom looking to get the job done, and I thought it was a professional performance from the players and credit to each and every one of them.
"Coming up here to Bolton is a difficult place, we worked in the week to make sure we got into our game and our rhythm."