Dragan Mrda scored twice in the first half as Serbia downed fellow World Cup finalists Japan 3-0 in a friendly at Nagai Stadium in Osaka today.
Midfielder Nemanja Tomic added to Mrda's brace early in the second half as an under-strength Serbia side made up of home-based players beat an equally second-string Japan, who were without their Europe-based players.
Serbia have been drawn in Group D alongside Germany, Australia and Ghana and begin their World Cup campaign against the African side on June 13.
Serbia assistant coach Radovan Curcic said: "It turned out to be a good game for our World Cup squad selection.
"We can go home with a good result in a good atmosphere. Although we hadn't had much time to prepare, it was a good occasion for us to show the quality of our league by playing against a good side.
"Japan is a well-trained team overall with high quality. Their players are at a high standard, but we took advantage of their mistakes well to create our chances."
The visitors made an encouraging start as Mrda hit the Japan post after just three minutes.
But the FK Vojvodina man was not to be denied after 15 minutes as Mrda latched on to a through ball before firing home from inside the area.
Serbia goalkeeper Zeljko Brkic denied Shimizu S-Pulse striker Shinji Okazaki and Yuzo Kurihara in quick succession to preserve the lead.
The eastern Europeans took full advantage midway through the first half as Japan goalkeeper Seigo Narazaki could only parry Mrda's initial shot and the striker stole in to double the visitors' lead.
Mrda and Milovan Milovic came close to doubling Serbia's advantage before the break as Japan were booed off at half-time by the 46,270 crowd in Osaka.
Japan coach Takeshi Okada responded by introducing winger Naohiro Takahara and striker Keiji Tamada in the second half.
Tokyo midfielder Naohiro Ishikawa was denied by Brkic just before the hour mark after linking up with Shunsuke Nakamura to test the Serbia goalkeeper from inside the area.
But on the hour mark Tomic curled home a superb free-kick from 25 yards before Japan's best chance arrived in stoppage time as substitute striker Kisho Yano hit the post from Ishikawa's corner.
"We were shaky in defence from the start and were often beaten by our opponents easily, although our defence got better in the second half," said Japan coach Okada.
"I thought we would be able to play better. However, when we don't have our regular players, I have to admit that we cannot play as much as we do with them."
Japan will next tackle South Korea on May 24 in Saitama before a pre-World Cup camp in Switzerland in late May ahead of kicking off their World Cup campaign against Cameroon on June 14 before facing Holland and Denmark in Group E.