Ladbrokes League One leaders Raith returned to winning ways with a 2-1 victory over Forfar at Stark's Park.
Rovers wrapped up the points when substitute John Baird slotted in a second with 14 minutes left.
Forfar substitute Connor Coupe scored a consolation for the visitors deep into stoppage time.
The Bairns took an early lead in the ninth minute through Lee Miller and McManus converted a second from the penalty spot in the 25th minute.
Striker McManus – who had found the net in each of his last three matches to move past 20 goals for the season – hit a fine second goal on the hour with a dipping free-kick.
Third-placed Airdrie beat East Fife 1-0 at the Excelsior Stadium.
Dale Carrick put the home side ahead in the 16th minute, knocking home a rebound after his penalty had been saved.
East Fife finished the match with 10 men when midfielder Ross Davidson was sent off for a second yellow card deep into stoppage time.
In-form Clyde chalked up a third straight win as they saw off Dumbarton 2-0.
David Goodwillie's close-range finish put the home side ahead four minutes into the second half.
Substitute John Rankin scored a second for the Bully Wee in stoppage time.
Paul Watson broke the deadlock five minutes before half-time.
With 15 minutes left, the Gable Endies got themselves back in front when substitute Craig Johnston knocked in a rebound.
Johnston made it 3-1 in stoppage-time, with Liam Callaghan then adding a late fourth to compound Stranraer's misery.