Playing in an earlier group, Loar was the first to break Paul McGinley's course record of 63, set in the final round at Yalong Bay Golf Club last year. Liang did it in a later group, and without any bogeys (Loar had one bogey and one eagle in his round).
There was almost no way McGinley's record -- which helped him force a playoff with eventual champion Paul Casey last year -- was going to last the day.
After Loar and Liang, Swede Joakim Haeggman, Australian Andrew Buckle, and South African Warren Abery all fired 9-under 63s to match the old mark and claim a share third place.
England's David Howell would have had a 63 if not for a bogey late in his round, which was followed by a pair of birdies that put him at 8 under and alone in sixth place.
In all, 30 players were 5 under or better in the first round -- including defending champion Casey, who shares seventh place with three other players at minus-7.
Calm conditions on the island of Hainan, in the South China Sea, provided an atmosphere ripe for low scoring. Just 35 in a field of 155 were over-par after the first round.
'When you come out here, especially on a day like today, you know you have to make birdies and keep making them,' Loar said. 'The scoring is going to be really good. The greens are perfect, [and] there is quite a bit of room to hit it.'
Loar, who tied for second at the Hong Kong Open in December, played the back nine first and opened with a birdie. He went on to eagle the 543-yard, par-5 13th -- a good thing for his record chances, because he bogeyed the par-3 15th.
After making the turn at minus-5, Loar collected five birdies on the front, including one at both par-5s: the 579-yard first and 580-yard ninth.
'It was a great way to start the week,' said Loar, the only left-hander on the Asian Tour.
Liang began his bogey-free round on the front nine and collected four birdies before the turn -- two on par-4s, one on a par-3 and one at the par-5 first.
A top-25 finisher in three of his last four events, Liang then scorched the back nine for six birdies, including one at each of the first three par-4s. He also birdied the 240-yard, par-3 15th and the 595-yard, par-5 16th.
Liang already owns the best showing ever by a Chinese player in this event, a third-place finish at the first TCL Classic in 2002. He has five career titles on the China Tour, which is a co-sponsor this week.
The 27-year-old found a little inspiration in playing partner Nick Dougherty of England.
'After he double-bogeyed he still played aggressively,' Liang said. 'The positive attitude he had taught me a lot. It showed that we all make mistakes, but watching him bounce back helped me.'