The match was new boss Andy Frame’s first home game in charge - and it couldm’t have started any better.
In only the second minute Jamie Watson sent over an excellent cross which eluded Dylan McGuigan but reached the evergreen Davie Dickson who made no mistake to put United ahead.
Three minutes later at the other end only a magnificent saving tackle by skipper Ryan Sullivan prevented a certain equaliser from a Renfrew attacker who was ready to pull the trigger.
Efforts from McGuigan, Tony Stevenson and a very much in-form Paddy McCabe tested the visiting defence as United played some excellent football despite the heavy pitch.
And they were rewarded in the 25th minute when, following a corner and a blocked Tony Stevenson shot, the ball broke to central defender Billy Robb who slammed home.
United should have added to their lead, but allowed Renfrew to come back into the game and in the 45th minute when Scott Morton fired a 20-yard rocket past Davie Buchanan to cut the deficitl.
The visitors almost equalised in the opening minutes of the second half, John Higgins clearing off the line with Buchanan beaten.
United gathered themselves and, from a Scott Murphy free-kick, Robb almost got his second with an effort which just cleared the bar.
But on the hour the home team were awarded a penalty when Jamie Watson was fouled as he jumped for a ball. Watson scored and Renfrew defender Martin Brogan was shown a red card leaving the visitors with ten men.
But the depleted away side were still a force to be reckoned with and in the 82nd minute Morton headed his second goal to ensure a tense last eight minutes.
But Frame’s men confidently played time out to give the new boss three consecutive wins and move United clear of the relegation area.