ROVERS’ five-game unbeaten run came to a truly demoralising end as they suffered their biggest league defeat of the season.

First-half goals from Medo and Joe Mason left Gary Bowyer’s desperately disappointing side with a mountain to climb.

There was no way back after Jay Spearing added a third right at the start of the second half and the seal was put on a derby drubbing in injury-time by substitute Andre Moritz.

To make matters worse Matt Kilgallon came off in the 73rd minute meaning injury-ravaged Rovers, who have slipped to 10th and six points off the play-offs, finished the match without a single recognised centre-back on the pitch.

Bolton played like a team possessed in the opening 10 minutes and would have found themselves two goals to the good had it not been for Paul Robinson and Kilgallon.

Firstly the back-pedalling Robinson palmed away a deflected Neil Danns drive that looked destined to loop into the net while Kilgallon – Rovers’ only fit and available centre-back after captain Grant Hanley was ruled out with a calf injury – produced a magnificent goal-line clearance to deny Mark Davies a certain goal.

Davies, finding space on the left, surged forward and fired a low shot toward goal that beat Robinson but not Kilgallon, who somehow managed to hack the ball away to safety.

But the fired-up hosts – with confidence clearly restored after a 2-0 home win over Watford seven days earlier ended their nine-game winless league run – could not cap their early dominance with a goal and the visitors went on to enjoy their best spell of the match.

Left-back Markus Olsson – brought in for his first league start of the campaign after Tommy Spurr was moved inside to cover for the absent Hanley – brought a flying save out of Bogdan after a Craig Conway cross was only half-cleared.

Bogdan then made a better, more important stop from stand-in Rovers skipper Jordan Rhodes in the 17th minute.

A raking pass over the top from Jason Lowe was headed into the path of Rhodes by Zat Knight.

The striker, drifting away from goal, did well to bring the ball under his control.

His effort, however, was charged down by the out-rushing Bogdan.

And six minutes later Bolton went in front thanks to Medo, who met a Danns cross and directed a clever header back across goal and past the wrong-footed Robinson from 15 yards.

After three straight clean sheets it was the first goal Rovers had conceded in 314 minutes of football.

Olsson, from fully 30 yards, did his best to cancel it out with a strike from range that Bogdan watched skim his crossbar, before Danns stung the hands of Robinson at the other end.

Robinson came to his side’s rescue again three minutes before the break when Lee Williamson was caught in possession by Spearing.

The former Liverpool midfielder sent Mason clean through on goal but his low shot was turned away by Robinson with the on-loan Cardiff City forward's second attempt going wide.

But Mason made no mistake in first-half injury-time, dragging past Robinson from just inside the area after Rovers made a complete hash of a clearance.

Boss Bowyer made a double change at the break as the fit-again Corry Evans and Luke Varney replaced Williamson and Chris Taylor, who had started in place of the injured Tom Cairney.

But it mattered little as two minutes after the restart Spearing – who turned down Rovers to sign for Bolton in the summer – made the game safe with a thunderous 25-yard drive that bounced down off the crossbar and was adjudged to have crossed the line by one of the assistant referees after play had initially been allowed to continue.

Rhodes, who has now not scored in any of his last nine outings, passed up a good opportunity when he headed an Olsson cross inches past the post.

But the game was up long before the final whistle and Lukas Jutkiewicz and Mason could have should have piled on the misery before Moritz did just that in injury-time as he beat Robinson from 25 yards.

And injury was added to insult when Kilgallon hobbled off to be replaced by Todd Kane.

It means Rovers, as things stand, do not have a single fit and available centre-back on their books with the East Lancashire derby at home to Burnley just a week away.

Bolton: Bogdan, Baptiste, Knight, Wheater, Ream, Spearing, Medo, Davies (Chung-Yong 77), Danns (Moritz 85), Jutkiewicz (Trotter 87), Mason. Subs not used: Lonergan, Hutton, Hall, Eagles.

Booked: Davies.

Goals: Medo 23, Mason 45, Spearing 47, Moritz 90.

Rovers: Robinson, Henley, Spurr, Kilgallon (Kane 73), Olsson, Taylor (Varney 46), Lowe, Williamson (Evans 46), Conway, Rhodes, Gestede. Subs not used: Eastwood, Dabo, Lenihan, Rittenberg.

Booked: Gestede.

Referee: Paul Tierney.

Attendance: 17,541 (2,743 away).