Shen Xue and Zhao Hongbo compete in the pairs short program during the ISU Four Continents Figure Skating Championships at the World Arena in Colorado Springs, Colorado. [AFP]

Shen and Zhao, two-time world champions who earned bronze at the 2006 Olympics, nailed their triple toe loops and landed their big throw triple loop.

Their only miscue came on their triple twist, when he caught her too close to his body and put her down hard on the ice.

"It was not a big deal, but we were conservative about it," Shen said. "I regret that because our score would have been higher, probably over 70, if we had gone for it."

Even with that flaw, they finished with a score of 69.29 points, almost 3.5 ahead of world champions Pang and Tong.

Pang and Tong landed their triple toe loop, triple twist and throw triple loop en route to a score of 65.80.

Their performance came despite the fact that their training is still disrupted by Pang's ongoiong recovery from kidney inflammation, while Tong is still recovering from injuries suffered in a car crash.

"It is better than it was, but I'm still not fully recovered," Pang said. "We need to take breaks in practice. My stamina is still not so good."

Americans Rena Inoue and John Baldwin, the defending pairs champions, were lying third after a short programme that included their throw triple Axel.

Canada's Olympic bronze medallist Jeffrey Buttle took the lead in the men's competition despite a flawed triple axel in his short programme.

Despite touching the ice with his hand on the jump, Buttle scored 77.72 points to lead Americans Jeremy Abbott (74.34) and Ryan Bradley (68.83).

In ice dance, Canadians Marie-France Dubreuil and Patrice Lauzon captured the lead after the compulsory dance ahead of Americans Tanith Belbin and Benjamin Agosto. Americans Meryl Davis and Charlie White were third with the original and free dance phases still to come.