Up to 4,000 Bolton supporters congregated outside the ground before kick-off to voice concern at owner Ken Anderson's handling of the club, before more unrest followed inside the stadium.

It was a relatively comfortable night for the Baggies as Jay Rodriguez put them ahead early on when he nodded home Craig Dawson's flicked header on the goal-line.

Sam Field wrapped up three points as he latched onto a ball cleverly dummied by Dwight Gayle to finish with ease past Bolton keeper Ben Alnwick.

Victory moves Darren Moore's side up to third in the table, four points behind leaders Leeds.

Gary O'Neil, who returned to Bolton last week after their registration embargo was lifted, had a great chance to put the hosts ahead early on as he glanced a close-range header across the face of goal, but they created few clear-cut opportunities.

Wanderers remain 23rd in the table, three points from safety, and are still the lowest scorers in the English Football League with just 18 goals in 28 matches.

The defeat also stretches a torrid run to just one victory in 18 Championship games.

Protests inside and outside ground

Police were forced to intervene after unrest in the home end

Anderson, who is out of the country, has said he is doing his utmost to sell the club and asked fans to be patient.

But thousands of supporters turned out to protest at their current financial state.

In September, former owner Eddie Davies gave Bolton a £5m loan four days before he died to help the club avoid going into administration.

Players' wages for November were also paid late and they were placed under a player registration embargo.

Protesting fans also showed support for club legend John McGinlay following his "removal of media privileges" after he voiced criticism in a BBC Radio Manchester fans' forum last week.

McGinlay joined the protest despite not being allowed to fulfil his media commitments inside the ground.

The protests continued inside the stadium, with supporters throwing tennis balls onto the pitch to delay kick-off while 'Anderson Out' banners were scattered throughout the crowd.

There was also unrest among a group of fans and stewards which quickly calmed down following intervention from police.

Bolton's next home game is a crucial fixture against Reading on Tuesday. The Royals are one point above Phil Parkinson's side.

Bolton manager Phil Parkinson told BBC Radio Manchester:

"We knew 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 about the focus.

"I felt we did that, we concentrated on what we had to do. We gave it everything to try and get something from the game.

"We've just got to regroup again and keep the positives of tonight and take it into the next couple of games."

West Brom manager Darren Moore told BBC WM 95.6:

"I thought it was a mature performance tonight, I thought it was a difficult game with the conditions and what was going on around the club.

"But, the players dealt with it really well and I thought their work in and out of possession was excellent.

"It was a mature, away-day performance and I'm obviously delighted to get the two goals and keep the clean sheet."