Issued by Paraguay to commemorate the 28th South American Tennis Championship held in Asunción (15–23 IX 1961), this sporty design features a racket striking a ball across the net, surrounded by colorful national-flag balls representing participating nations. The bold geometric layout and mid-century graphics capture the optimism of early international sporting events in South America. Printed in rich blues and ochres, it stands out strongly in any sports or tennis thematic collection. A desirable classic for both sports philately and Paraguay commemorative issues, especially in clean MNH condition.