Gary Mackay-Steven's second-half strike was all United had to show for their domination at Tannadice, and although it brought an end to their run of high-scoring victories the win moved McNamara's men into second place in the Scottish Premiership.
"The most important thing is the three points," said McNamara. "I thought we kept plugging away at them, we were very patient, but we got our just rewards in the game.
"We could have had a few more goals, but the good thing is we're creating chances, and from me as an ex-defender, it's good to get a clean sheet.
"It's important - there's a busy period coming up with the games we've got, so we need everybody in the squad and when they came on it put Ross county on the back foot.
"Given the start we had at the start of the season, the first few games there was a few question marks over the squad, but I'm delighted for the lads and the effort they've put in, their desire to keep going in games - they get the rewards for it."
Ross County manager Derek Adams praised his charges for their resolute display against in-form opponents.
"A lot of teams have been heavily defeated by Dundee United this season," said Adams. "I'm just delighted we put up a good show.
"I think the players are disappointed to come away with nothing, because we kept Dundee United very quiet from the point of view that they hadn't scored any goals up until we made a mistake," said Adams.
"We played well, but Dundee United were excellent at times. Obviously, they've got the quality throughout their side, but we started well, and we were on the front foot.
"We caused them a few problems, which we knew we could - but Dundee United are playing with a lot of confidence."