The Swindon boss, who had two spells at Huddersfield, famously scored a goal in the Terriers' play-off semi-final victory over Lincoln and his new charges did him proud.
Swindon, rock bottom of League One, threatened to embarrass the joint leaders and thoroughly deserved a second successive league point.
Onuora is still waiting for his first league victory but his side went close against a Huddersfield team which had too many players out of form.
Midfielder Andy Gurney was the main dangerman for the Robins and his dead ball skills ensured a difficult afternoon for the home side.
Gurney saw a free-kick deflected wide and Paul Rachubka clutched another at the second attempt.
Ricky Shakes raced away down the right but his cross-cum-shot shot drifted on to the roof of the net.
Sean O'Hanlon rose unmarked for a Gurney corner and should have hit the target.
Swindon took the lead 10 minutes before the break when Nathan Clarke was harshly adjudged to have handled Steve Jenkins' ball into the box and Gurney confidently smashed home the spot-kick.
Huddersfield improved in the second half and keeper Tom Heaton saved from Pawel Abbott as the home side pressed forward.
The Terriers equalised on 54 minutes when Chris Brandon turned home Andy Holdsworth's deep cross.
That should have inspired Huddersfield but instead Swindon went on the attack and Andrew Nicholas forced Rachubka into a fine save.
David Stroud fired wide and the Rachubka pulled off his best save when he tipped Hameur Bouazza's powerful drive wide.
Huddersfield staged a frantic finale in four minutes of stoppage time and Abbot headed wide when well placed but a point was the least that Swindon deserved.