Andy Murray said he is not unduly concerned by his current form despite being knocked out of the Japan Open in the second round by Jiri Novak, 6-3, 7-6.
The Scot, who was playing his first match in the singles in Tokyo having received a bye in the first round, was up against the 31-year-old for the first time. The Czech took the first set with ease and looked to be heading the same way in the second as he raced to a 4-1 lead, but Murray lifted himself to make it 6-6. However, Novak ensured the 19-year-old's fightback ended there, by raising his game another level to take the set 7-6.
Murray defended his recent form, having been knocked out of the Thailand Open by Tim Henman last week in the first round. "Every young player goes through a patch where he's not playing well," he said. "You can't expect to get to the semi-finals every week unless you're Roger Federer or Rafael Nadal. They are the only two who can do it. I wasn't looking that far ahead.
"It's not like I lost to bad players," he added. "Henman has been at the top of the game for a long time. Novak was No 5 in the world [in 2002]. I did well to fight back into the match but unfortunately I couldn't quite turn it around."
Murray will now concentrate on progressing in the doubles with his brother, Jamie, after the pair beat Eric Butorac and Travis Parrott 7-5, 6-3 on Tuesday.
Germany's Benjamin Becker, best known as the man who ushered Andre Agassi into retirement at last month's US Open, will face Novak next after thrashing Thailand's Danai Udomchoke 6-2, 6-1.
Federer secured a place in the third round with a straight-sets victory but he was given a fright by Viktor Troicki, a player 275 places below him in the rankings. The world No 1, in his first singles tournament since the US Open, prevailed 7-6, 7-6 in an hour and 43 minutes to earn a third-round meeting with the defending champion, Wesley Moodie. The 13th-seeded South African had seen off the Austrian Stefan Koubek 6-3, 6-4 earlier.
"I made it hard on myself," Federer said. "Thank God I have the ability to play well when I really need it. It was a tough match and I'm really happy I came through." Federer improved his win-loss record for the year to 73-5, but said: "I did not want to take too many risks. I wanted to get a rhythm for myself."
The second seeded Tommy Robredo, of Spain, booked his place in the last 16 with a convincing 6-4, 6-1 win over the Taiwanese qualifier Lu Yen-hsun. Jarkko Nieminen, of Finland, also advanced to the third round, the fifth seed beating the German Lars Burgsmüller 7-5, 7-6 on an outside court.