The 41-year-old produced a measured performance at the par-71 Macau Golf and Country Club shooting four birdies against a lone bogey to set the early pace with rookie Ben Campbell of New Zealand, who shot the tournament's first hole-in-one, and Finland's Kalle Samooja.
Birthday boy Ernie Els of South Africa salvaged a 71 after fighting back from being four-over-par through his opening seven holes to lie three shots behind the leaders.
Two-time champion Zhang Lian-wei rolled back the years with a 69 for a share of fourth place with Thai teenager Jazz Janewattananond and Prom Meesawat, Australian Marcus Both and Bangladeshi Siddikur, who led on four-under before bogeying his closing two holes.
Barr broke onto the Asian scene 10-years-ago here when he lost in a play-off to Colin Montgomerie after agonisingly lipping out a birdie putt for victory on the 72nd hole.
"I hit the ball good enough and made some up and downs early in the round and kept it going. The ball wasn't flying early this morning. It was very windy, very dark and murky. I knew it was going to be tough. I'm not sure what the forecast is going to be but if it stays like this, I'm actually looking forward to it," said Barr, who is still seeking the elusive first Asian Tour victory.
68 - Scott BARR (AUS), Kalle SAMOOJA (FIN), Ben CAMPBELL (NZL).
69 - Marcus BOTH (AUS), ZHANG Lian-wei (CHN), Jazz JANEWATTANANOND (THA), Prom MEESAWAT (THA), SIDDIKUR (BAN), Jason KNUTZON (USA).
70 - Sujjan SINGH (IND), HUNG Chien-yao (TPE), Jeev Milkha SINGH (IND), LU Wei-chih (TPE), Elmer SALVADOR (PHI), CHAN Yih-shin (TPE), Chawalit PLAPHOL (THA), Adam GROOM (AUS), Jay BAYRON (PHI), LU Wen-teh (TPE), James BYRNE (SCO), Simon GRIFFITHS (ENG).
71 - Ernie ELS (RSA), Ryan MCCARTHY (AUS), Sam BRAZEL (AUS), Daisuke KATAOKA (JPN), TSAI Chi-huang (TPE), Nicolas MEITINGER (GER), Rory HIE (INA), Sutijet KOORATANAPISAN (THA), LIANG Wen-chong (CHN), Antonio LASCUNA (PHI), BAEK Seuk-hyun (KOR), LEE Sung (KOR), Anthony KANG (USA), Adam BLYTH (AUS), Thammanoon SRIROJ (THA).
72 - LAM Chih Bing (SIN), Carlos PIGEM (ESP), Adilson DA SILVA (BRA), Stephen LEWTON (ENG), S.S.P CHOWRASIA (IND), CHIANG Chen-chih (TPE), Thanyakon KHRONGPHA (THA), Timothy TANG (HKG), David PALM (SWE), Arjun ATWAL (IND), Darren BECK (AUS), Kwanchai TANNIN (THA), Himmat RAI (IND), Peter GUSTAFSSON (SWE), YEH Chang-ting (TPE), Shankar DAS (IND).
--IANS (Posted on 17-10-2013)