The striker’s arrival from Portsmouth on a permanent deal was only announced two hours before kick-off and he struck the only goal to secure Fleetwood’s second away win of the season.

In a dour affair, it was Fleetwood who showed the greater threat as Doncaster struggled for spark in the the final third.

Goalkeeper Pontus Dahlberg twice came to Doncaster’s rescue, first blocking a Cian Hayes drive with his legs before batting away a Danny Andrew free-kick.

RESULT: Doncaster Rovers 1-0 Fleetwood Town. Picture: Gary Longbottom.

Fleetwood did break the deadlock after 50 minutes when Harrison met a low ball across goal and fired in from close range.

Doncaster’s best chance of the game came almost immediately after when Tommy Rowe flicked a header narrowly wide from a corner.

It was comfortable for Fleetwood, though substitute Charlie Seaman almost snatched a point for Rovers with a powerful drive in stoppage time that Alex Cairns pushed away.

The result leaves Rovers nine points behind Town, who occupy 20th place in the League One table.

Doncaster Rovers 0 Fleetwood Town 1: Rovers lose vital ground in relegation battle against League One rivals