The 19-year-old Tanzanian-born winger, who starred at Adelaide United but didn't make the grade at German champions Bayern Munich, curled a glorious 25-yard free-kick home to give the second-tier Hornets the lead at Swansea in the 35th minute of their 1-1 draw on Saturday.
The belting strike capped another striking performance from the 19-year-old, who proved a real handful for the home defence all afternoon with his speed and trickery until he was brought off just before the hour as a precaution when he appeared to suffer a hamstring knock.
Snapped up from the Bundesliga giants on a five-year deal, Irankunda has made a big impression since arriving in England, and was quick to tell reporters how his ambition was to "make the crowd go wild" at Vicarage Road.
He did just that when he won the foul just after the half-hour and then picked himself up to whip the ball up and over the Welsh side's wall and into the left-hand corner - a goal similar to one he had scored for the Reds in the A-league Men - much to the delight of the travelling fans behind the goal.
But when the teenager went off, soon after being fouled by Swansea's new signing Marko Stamenic, Watford's impetus seemed to be lost and Zan Vipotnik came off the bench for the Swans to rescue a point with his glancing header eight minutes from time.
Irankunda has been enjoying being back in the thick of the action after his confidence took a bit of a hit in Germany.
"It's been good," the Australia international had said earlier in the week. "I feel like myself again, a whole lot more confident. It's fun to come to training every day.
"I love playing here. I've enjoyed the first few minutes and training sessions."
16°C