( CNN ) -- Chinese tennis star Li Na revealed she is reaping the rewards of a brutal preseason training regime after reaching the semifinals of the Australian Open for the third time in four years . Sixth seed Li beat the Poland 's world No . 4 Agnieszka Radwanska on Tuesday 7-5 6-3 to advance to the last four of a major for the first time since becoming Asia 's first grand slam singles champion at the 2011 French Open . Last year Li began working with Carlos Rodriguez , former trainer of seven-time grand slam winner Justine Henin , after deciding to end her professional relationship with husband Jiang Shan . `` We train every day for five , six hours , but not only playing tennis , '' the 30-year-old told reporters after setting up a tie with world No . 2 Maria Sharapova . `` Tennis was like maybe two , three hours . Fitness was for two or three hours as well . `` First time I was training with him , I was so excited , but after three days , I was dying . My husband did n't come with me to Beijing . `` I called him and said , 'Carlos is crazy ' . He was like , 'Why ? ' I described the program to him . He was like , 'Do n't joke . ' I said , 'Hey , listen , I 'm not making a joke . ' `` Li , the Australian Open runner-up in 2011 , said ending her tennis partnership with her husband had caused many people to think they had also ended their personal relationship . `` He was doing a very good job , '' she said . `` But between husband and the coach , it is very tough . Sometimes , if he said 'we should do something ' I was feeling tired ... That 's why sometimes we have to fight . `` The funny thing is I think two years ago someone said I was divorced . They were asking me . They asked me , 'Li Na , we hear you are divorced . ' `` The extra fitness work paid off for Li as she ground out a victory in one hour and 42 minutes against an opponent who had beaten her at the recent Sydney International event and went into Melbourne undefeated with two titles to her name in 2013 . `` She 's a tough player , '' Li said of Radwanska , who had not dropped a set this year before the match . `` I was feeling against a wall . She can hit everywhere , but without a mistake . You have to focus on every shot . Not every point , every shot . If you hit slow or short , she 'll attack . '' Sharapova booked her place in the last four with a fifth consecutive straight-sets victory . The four-time grand slam winner made light work of fellow Russian Ekaterina Makarova , beating the 19th seed 6-2 6-2 . The 2008 Melbourne champion has dropped just nine games en route to the semifinals , a record for the tournament , but dismissed suggestions that her relatively untroubled run to the latter stages would leave her unprepared for Li . She has already earned $ 500,000 in prize money for just 315 minutes on court -- $ 1,587.30 a minute -- despite coming into the season 's opening grand slam under an injury cloud . `` Well , going into the match , my goal is not really to be tested , '' joked Sharapova , who lost last year 's final against world No . 1 Victoria Azarenka . `` If I do come into a situation where I feel like I have to pull through or I 'm not playing my best tennis or she 's up and I have to find a way to win , then that 's what you have on that given day . ''
Li Na benefiting from a punishing training regime ahead of the tennis season . World No . 6 beat fourth seed Agnieszka Holland to reach Australian Open semifinals . Chinese star will face Maria Sharapova , who beat compatriot Ekaterina Makarova 6 - 1 6 - 2 . Russian second seed has lost just nine games -- a record -- on way to the last four .