MASON, Ohio (AP)—Novak Djokovic gets another chance at the one that keeps getting away.
Four times, the world's No. 1 player has reached the final of the Western & Southern Open. He's finished as the runner-up all four times in the only Masters tournament where he has never gotten to raise the winner's trophy.
He's the top seed in the tournament that opened on Sunday with a pair of men's matches. And he's the one to watch this week when it comes to tennis history as well. A title in Cincinnati would make him the first player to win all nine ATP Masters events.
This isn't just another week for Djokovic.
''That always adds more importance to this tournament for me,'' he said Sunday after a two-hour practice. ''I do care to win this title a lot. Four times I've lost in the finals and I haven't been really close in those finals.
''Playing four times in the finals is a great result. Hopefully I can go a step farther this time.''
Defending champion Rafael Nadal injured his right wrist and is out of the tournament, leaving one less obstacle to Djokovic's quest. Nadal, Roger Federer and Andy Murray have won eight of the last nine titles in Cincinnati.
Lleyton Hewitt fought off eight of 12 break points and rallied to beat Jurgen Melzer 3-6, 6-4, 6-4 in an opening match that lasted 2 hours, 6 minutes. Sam Querrey finished off Alejandro Falla 6-3, 6-1 in only 46 minutes.
''Everything was kind of working for me tonight,'' Querrey said.
Djokovic's focus on Sunday was getting accustomed to the fast courts and the humid conditions. Last July, he beat Federer in five sets to win his second Wimbledon title, but has struggled in the transition to hard courts.
In Toronto last week, Jo-Wilfried Tsonga upset Djokovic on Thursday and knocked out Murray a day later. Djokovic said the courts in Cincinnati don't seem quite as fast as those in Toronto, which should help him.
''I know what I need to do to get myself in the right shape, and hopefully I'll do it,'' he said. ''It's easier said than done.''
Murray beat Djokovic for the Cincinnati title in 2008 and 2011. His focus this week is to get better at holding leads late in matches, which has been a problem all season. He listed all the times he's let a set slip away, including last week during his loss in Toronto.
''I messed up a couple of matches this year, to be honest,'' Murray said. ''My year could have been a lot different if I finished those matches off. I need to stop messing up when I'm ahead.''
John Isner had one of his best tournaments in Cincinnati last year, reaching the final before losing to Nadal in a pair of tiebreakers. The showing has given him a lot of confidence for his return.
''I played very well from the get-go,'' Isner said. ''My opening match, I played extremely well. I beat a handful of very good players. Every match was close. I just got on a roll and embraced everything. At a certain point, I had nothing to lose.''
Serena Williams is the top seed in the women's draw. She fell apart in the Cincinnati final last year, losing in three sets to Victoria Azarenka. Williams lost to sister Venus in the semifinals at Montreal on Saturday.
Azarenka has missed much of the season because of an injured left foot. She fell during a match in Montreal last week and has a sore knee, another concern as she defends her title in Cincinnati.
She's had few highlights all year.
''There's not much to describe,'' Azarenka said Sunday. ''There's been not so much happening for me this year. I haven't played so much. It's been mostly about recovering and getting back.''