<p>Japanese spearhead Kei Nishikori felt he played some of his best tennis since elbow surgery in 2019 Monday, but it still wasn't enough to prevent a first-round defeat at the Australian Open.</p>.<p>Nishikori, a four-time quarter-finalist at Melbourne Park who has slid down the rankings to 41, was outlasted by Spain's Pablo Carreno-Busta 7-5, 7-6 (7/4), 6-2.</p>.<p>The 31-year-old, who is now fit and healthy, had been hoping for a good showing at the opening Grand Slam of the year as he attempts to return to the top 10. He reached a career-high ranking of four in 2015.</p>.<p>"Well, tough because I thought I was playing well but Carreno was playing better today," said Nishikori, who missed most of last season recovering from the injury.</p>.<p>"I thought I was playing pretty high level. For me, I played, I think, one of the best tennis so far, including last year after coming back.</p>.<p>"I was kind of happy the way I'm playing with this level, but still not enough to beat this guy."</p>.<p>Carreno Busta came into the clash after solid preparations at the ATP Cup, where he won two singles matches and lost one.</p>.<p>Another Spaniard, Pedro Martinez, piled more misery on Japan by beating Yoshihito Nishioka 6-7 (3/7), 6-1, 6-1, 6-1 to end the Japanese number two's campaign.</p>
<p>Japanese spearhead Kei Nishikori felt he played some of his best tennis since elbow surgery in 2019 Monday, but it still wasn't enough to prevent a first-round defeat at the Australian Open.</p>.<p>Nishikori, a four-time quarter-finalist at Melbourne Park who has slid down the rankings to 41, was outlasted by Spain's Pablo Carreno-Busta 7-5, 7-6 (7/4), 6-2.</p>.<p>The 31-year-old, who is now fit and healthy, had been hoping for a good showing at the opening Grand Slam of the year as he attempts to return to the top 10. He reached a career-high ranking of four in 2015.</p>.<p>"Well, tough because I thought I was playing well but Carreno was playing better today," said Nishikori, who missed most of last season recovering from the injury.</p>.<p>"I thought I was playing pretty high level. For me, I played, I think, one of the best tennis so far, including last year after coming back.</p>.<p>"I was kind of happy the way I'm playing with this level, but still not enough to beat this guy."</p>.<p>Carreno Busta came into the clash after solid preparations at the ATP Cup, where he won two singles matches and lost one.</p>.<p>Another Spaniard, Pedro Martinez, piled more misery on Japan by beating Yoshihito Nishioka 6-7 (3/7), 6-1, 6-1, 6-1 to end the Japanese number two's campaign.</p>