Riga appeared to be on a hiding to nothing in front of a Valley faithful unhappy that controversial owner Roland Duchatelet had sacked club legend Chris Powell and replaced him with the unknown Belgian.
Powell was axed on Tuesday morning having clashed with Duchatelet over the club's recruitment policy - namely bringing in a host of players from Standard Liege and other clubs he owns.
Tellingly Powell did not name one of those players in his starting line-up for what proved to be his final game in charge, Sunday's FA Cup defeat at Sheffield United.
But Riga, a former coach at Standard, immediately called up two of them, midfielder Astrit Ajdarevic and striker Reza Ghoochannejhad.
The 56-year-old received the welcome he probably anticipated when he strode out of the tunnel, a smattering of applause and a fair few boos.
Then when the clock reached three minutes - Powell's shirt number as a Charlton player - the fans began clapping and singing his name for 60 seconds.
Yet seconds after Powell's ovation had died down, Ajdarevic almost opened the scoring for the hosts with a long-range drive which had Alex Smithies diving at full stretch.
And as the first half wore on some of Charlton's passing had become sharper than the new manager's suit.
One Ghoochannejhad dummy sent Lawrie Wilson clear down the right and had the sceptics in the home crowd on their feet.
Moments later an extravagant backheel from Ajdaveric had the same effect.
Homegrown winger Callum Harriott also got in the act, his neat dummy making space for Rhoys Wiggins to race down the left.
Of course some of the old failings remained, namely putting the ball in the net and Ghoochannejhad was unable to turn in the resulting cross from Wiggins.
Michael Morrison and Ghoochannejhad both volleyed Johnnie Jackson corners wide and Ajdaveric was off target with a header.
In the second half Marvin Sordell was twice sent clean through but scuffed his first effort wide and was denied by Smithies with the second.
So goalscoring remains a problem, but Charlton did manage to restrict Huddersfield to a few chances from long range, with Ben Hamer keeping out Nahki Wells' effort and also denying Danny Ward and Jonathan Hogg.
And when Wells did manage to take the ball round Hamer early in the second half, Dorian Dervite had got back in time to clear his angled shot off the line.
In the end Riga had to settle for a point, as well as winning over a few doubters.
And his popularity will surely soar if Charlton can take three points from a crunch relegation clash at derby rivals Millwall on Saturday.