Flannigan scored after only six minutes after being set up by Andy Graham but although they contined to press, they had to wait until injury-time to wrap up the points when Renton forced the ball home.
Arbroath kept up their challenge with a 2-0 win at Queen’s Park. Gavin Swankie gave them the lead with a decisive strike and Colin Hamilton netted the second after 54 minutes.
A double from Ryan Conroy gave Airdrieonians a 2-0 home win over Stranraer. Jordan Allan had the ball in the net early on for Airdrie but had clearly handled the ball before scoring and it did not count.
Ryan Wallace then came close at the other end with a right-foot shot which slipped narrowly past and came even closer moments later after a flowing Stranraer move but his shot struck the post.
Conroy broke the deadlock after 61 minutes when he slotted home after a cutback from Luke Watt and eight minutes later found the top corner of the net to settle it.He was denied his hat-trick in the closing stages by a stunning fingertip save from Cameron Belford.
Forfar Athletic climbed away from the foot of the table with a 2-0 win over East Fife at Station Park.
Forfar took the lead in 59 minutes when Eddie Malone headed past Mark Hurst and doubled their advantage eight minutes later through Michael Travis.