Naomi Osaka's Australian Open campaign has taken on an element of doubt after the four-time Grand Slam champion and former No. 1 suffered an apparent injury Sunday while playing the final of a WTA tournament in Auckland.

Former world No. 1 Naomi Osaka retired from the ASB Classic final in Auckland on Sunday due to an abdominal injury after winning the first set against Clara Tauson.

Naomi Osaka's quest for a first title in four years ended in heartbreak as the former world number one retired with an injury after winning the opening set of the Auckland Classic final against Denmark's Clara Tauson on Sunday.

Osaka retired from the ASB Classic final in Auckland due to an abdominal injury. The four-time Grand Slam champion won the first set against Clara Tauson 6-4 before taking an immediate medical time-out that would signal the end of the match. Due to injury, Osaka has retired from the match. Clara Tauson is the champion with a final score of 4-6.

Naomi Osaka has made her first WTA final in three years and she is a win away from lifting her first title as a mom. On Saturday, the seventh-seeded Japanese ousted world No. 82 Alycia Parks 6-4 6-2 in the semifinal of the WTA 250 tournament in Auckland.

Naomi Osaka could possibly start her Auckland campaign by meeting two qualifiers but then it could also get significantly tougher for the four-time Grand Slam champion.