Dunlop Yellow Australian Open Tennis Balls (4 Ball), Sports Direct. The Official Ball of the Australian Open The 1st Grand Slam tournament of the year uses this high-performance tennis ball. HD Core and HD PRO Cloth technologies make it easier to play on all surfaces. Wherever you play, however you train. One thing underpins it all, the Dunlop tennis ball. Obsessively crafted, meticulously engineered, officially endorsed. The Official Ball of the Australian Open. The Australian Open ball is approved by the ITF.Looking for alternatives to stores like JD Sports, eBay, SHEIN, ASOS, Next, Best Choice UK, Very, Decathlon UK, Argos, schuh, Temu, BuyBetter, or Nike Official? Discover our unique selection.