Zuru has already won three preliminary injunctions against Telebrands for its balloon products range, including its Battle Balloons, Balloon Bonanza and Easy Einstein products.
A jury has now found in Zuru's favour over the Battle Balloon product line, including Balloon Bonanza HD and Battle Balloon Color Burst.
Zuru was awarded lost profits and damages of US$12,250,000 (about $18m).
Chief operating officer Anna Mowbray said the company was committed to "continuously fighting what we believe are knock-off companies like Telebrands who try to undercut inventors and claim innovations as their own".
"We are confident that the US legal system will help us continue to send this message.
"Moreover, we are looking forward to an award of enhanced damages above and beyond the $12,250,000 based on findings of Telebrands' wilful misconduct."
Zuru has two additional cases against Telebrands, involving the Balloon Bonanza and Easy Einsteins products, which it says are also copies of its products.
Lab testing on samples of Telebrands' Easy Einsteins product had also showed it contained toxic chemicals well in excess of legal limits for children's toys.
Telebrands has argued that following the lab tests it was already withdrawing the product from the market.