Nani, Wayne Rooney and Lee Martin claimed the goals as United overcame stifling conditions in Guangdong Province to put a winning seal on their hugely successful tour of the region that has also seen stops in Japan, South Korea and tiny Macau.

Having won two and drawn one of their three tour games before this clash at the Guangdong Olympic Stadium, United boss Alex Ferguson opted to rest the likes of Edwin van der Sar, Patrice Evra and Cristiano Ronaldo in favour of untried youngsters.

But England forward Alan Smith was absent from the starting line-up for the fourth game in a row, making it almost certain that the former Leeds striker will be on his way out of Old Trafford when they return to England on Saturday.

With Smith on the bench again, Ferguson chose Rooney and Dong Fangzhuo up front and the pair linked well before Rooney put United ahead from the penalty spot on 18 minutes.

Rooney had already sent a 30-yard effort dipping over keeper Li Shuai's crossbar on six minutes before crossing for Dong to head narrowly over seven minutes later.

Star man Rooney broke the deadlock five minutes later, though, when he sent the keeper the wrong way from the spot after Chinese referee Wan Daxue had awarded a penalty following Oliveira's clumsy challenge on Michael Carrick.

Guangzhou found it difficult even to get out of their own half and both Nani and Carrick went close from long range before Rooney struck a close range effort against the post.

Portuguese youngster Nani doubled United's lead on 42 minutes with a wonder goal after being teed-up by Rooney. From a tight angle on the left, the 17.3 million pounds (35.5 million dollars) winger chipped in off the far post.

But the 20-year-old passed up on his trademark somersault celebration after being banned from performing the spectacular party trick by United boss Ferguson.

United almost started the second half without a goalkeeper after the referee whistled for kick-off before youngster Tom Heaton had even taken to the pitch to replace Polish stopper Tomasz Kuszczak.

But the Premiership champions could probably have played the whole of the second period without a keeper due to their control of the game and United extended their lead on 52 minutes when Martin netted a superb long-range effort.

The midfielder, who spent part of last season on loan at Scottish giants Rangers, cut inside from the left before unleashing a 30-yard effort that left the keeper totally helpless.

With the game won, Ferguson delighted the fanatical Chinese crowd by introducing Portuguese star Cristiano Ronaldo for the final 12 minutes, but the double footballer of the year could not add to the score during his brief cameo.