McNamara was the focus of the build-up to the first Scottish Premiership clash after leaving Thistle for Tannadice in January before the Maryhill club went on to join their former boss in the top flight.
The split proved acrimonious as the two clubs became embroiled in a lengthy and sometimes public dispute over compensation before finally reaching a compromise in the summer.
And McNamara and assistant Simon Donnelly emerged from the tunnel to a chorus of boos just as Thistle chairman David Beattie was due to unfurl the First Division title flag.
McNamara was slightly frustrated that United did not finish off one of their chances, with David Goodwillie coming close on several occasions, but was satisfied with the night's work in a hostile environment.
"It's been the build-up since the wee guy picked the fixture out in Canada," said McNamara, alluding to the computer programming company used by the Scottish Professional Football League's fixtures team.
"I'm delighted to come back here regardless off all the stuff surrounding it, I'm just disappointed not to get three points.
"It was fine, even walking to the dugout in front of all the United fans.
"Again, everything I have done, I wouldn't change anything.
"I'm delighted to be where I am and I want to be a success at United."
Asked if he was happy with a point, he said: "I'm always wanting the three but it could have gone either way and in reflection a point was a fair result."
McNamara's successor, Alan Archibald, was pleased with his team's return to the top level.
"We acquitted ourselves very well," he said. "For spells we controlled the game, we were just missing that cutting edge.
"It was an entertaining 0-0 draw, I thoroughly enjoyed it."
Both managers disagreed over the 70th-minute flashpoint which saw Callum Butcher escape a red card for a lunging challenge on Thistle midfielder Gary Fraser. Both players were booked after a melee.
"By the letter of the law it was a red card," Archibald said. "But I'm not going to moan about it, I put in a few of those challenges myself."
McNamara said: "I thought it was similar to ones before it on Ryan Dow and Paul Paton.
"It got a bit heated after that, even on the bench."
- Sports & Recreation
- David Beattie
- David Goodwillie