Tennis superstar Naomi Osaka and her rapper boyfriend, Cordae, are going stronger than ever and have NOT broken up ... despite reports claiming otherwise.

The rumors began to swirl on social media this week ... when one blog stated the two 24-year-olds had called it quits.

Sources close to the couple tell TMZ Sports the Japanese pro and "Chronicles" MC are actually doing better than ever ... and they're most definitely still "happily in love."

In fact, we're told Cordae and NO have been spending even more time together recently ... which makes the initial report even more of a head-scratcher.

As we previously reported, the duo first started going public with their relationship in 2019 ... and have been each other's biggest supporters during album releases and tennis matches.

Speaking of, Cordae is fresh off a buzzing performance at Lollapalooza ... and Osaka just made her first return to the court since May, winning her first-round match of the Silicon Valley Classic.

Osaka said after the match she was "really happy" to be back on the court ... so it sounds like everything's going well for the superstar.