"Your success represents a new breakthrough in our manned space program," Hu told the astronauts in a scripted exchange that was also broadcast live.
"The motherland and the people thank you," said Hu, who is chairman of the powerful Communist Party and government military committees that oversee the space program.
The spacewalk was mainly aimed at testing China's mastery of the technology. Mission commander Zhai Zhigang's sole task was to retrieve a rack attached to the outside of the orbital module containing an experiment involving solid lubricants.
Tethered to handles attached to the Shenzhou 7 ship's orbital module, Zhai remained outside for about 13 minutes before climbing back inside through the open hatch.
"Greetings to all the people of the nation and all the people of the world," Zhai said into an external camera he floated halfway out of the open hatch.
Fellow astronaut Liu Boming also emerged briefly from the capsule to hand Zhai a Chinese flag. The third crew member, Jing Haipeng, monitored the ship from inside the re-entry module.
While successful, the spacewalk wasn't without its anxious moments.
Zhai, a 41-year-old fighter pilot, appeared to struggle with the hatch and then a fire alarm was triggered in the orbiter as he began the spacewalk.
Wang Zhaoyao, deputy director of manned space flight, conceded the combined effects of weightlessness and depressurization on the hatch opening operation hadn't been fully anticipated. He blamed a faulty sensor for the fire alarm.
"There were be no impact on the rest of the mission," Wang said.
The spacewalk required astronauts to first depressurize and then repressurize the orbital module and proved the effectiveness of Zhai's Feitian space suit, produced by China at a cost of $4.4 million. Liu wore a nearly identical Russian-made Orlan suit, state media said.
Following the spacewalk, the astronauts released an 88-pound satellite to circle the orbiter and send back images to mission control.
The spacewalk was an opening step for China's plan to assemble a space station from two Shenzhou orbital modules, the next major goal of the manned space program. China is also pursuing lunar exploration and may attempt to land a man on the moon in the next decade - possibly ahead of NASA's 2020 target date for returning to the moon.
China launched its first manned mission, Shenzhou 5, in 2003, becoming only the third country after Russia and the United States to launch a man into space. That was followed by a two-man mission in 2005.
Along with challenging Russia and the U.S., the spacewalk ups the ante in China's competition with Asia's other aspiring space powers, Japan and India. China's advances have spurred space spending by those two nations, partly for bragging rights but also in search of economic benefits such as a bigger slice of the commercial satellite launching business.
In step with its growing list of achievements, China's military-backed space program has grown progressively less secretive and officials have hinted in recent days at a desire for greater cooperation with other nations. China plans to mass produce the next version of the Shenzhou ship to service a future space station and says it may make such missions available to other countries.
Cooperation between China and other nations has so far been limited. The U.S. has refused Chinese involvement in the international space station operated with Russia for fear Beijing could gain technical secrets applicable to its arms industry.
A Chinese space program official said earlier that Russian technicians would assist in Saturday's spacewalk, but it wasn't clear what role they played.
Since blasting off from the Jiuquan launch base in northwestern China, the astronauts had been largely occupied with preparing their suits and adapting to zero gravity. Cameras inside the re-entry vehicle showed them going through checklists and napping.
Meals aboard the craft have followed a typical Chinese menu, featuring versions of kung pao chicken, shrimp and dried fruit, the official Xinhua News Agency said.
