No. 5 seed Kerber out of Australian Open

Fifth-seeded Angelique Kerber has been beaten by Russian Ekaterina Makarova in the fourth round of the Australian Open 7-5, 6-4.

Kerber, a semifinalist at Wimbledon last year, received treatment for her back during the match Sunday. She's the highest women's seed to lose so far this year at Melbourne Park.

Makarova, the 19th-seeded player, beat Serena Williams last year to reach the quarterfinals of the Australian Open - her best result at a Grand Slam.

Kerber had beaten Makarova three times last year, including in the second round at Wimbledon.