Hickman, riding the Aspire-Ho by Bathams Racing BMW, set his best lap in 2m 25.429s, which gave the English rider the top spot by just under one second from team-mate Michael Rutter, who is riding the Honda RC213V-S.
Ex-Moto3 rider Danny Webb was third fastest on the Penz BMW, 1.6s adrift, while Martin Jessopp was fourth on the PBM Ducati.
Lincolnshire’s Gary Johnson left it late to slot into fifth on the Briggs Kawasaki ahead of Horst Saiger, who completed the top six on his Yamaha.
Aussie David Johnson was next on the PR Racing BMW with Dublin’s Derek Sheils eighth (Penz BMW).
John McGuinness (PBM Ducati), who is making his Macau return after missing the event in 2017 through injury, was ninth. The top ten was completed by Didier Grams.
Newcomers Davey Todd (Penz BMW) and Paul Jordan from Magherafelt (Dafabet Devitt Kawasaki) were 12th and 15th respectively, with Skerries man Michael Sweeney 14th (MJR BMW). Davy Morgan from Saintfield was 26th on his DM71 BMW.
In an incident-hit earlier opening free practice session, Rutter topped the times by 1.2 seconds from Hickman.
Two crashes brought out the red flags, with newcomer Andrew Dudgeon coming off only minutes into the session, while a further stoppage occurred after Raul Torres Martinez crashed at Mandarin, with his bike bursting into flames.
As a result of the accidents, the session ran for a total of only 15 minutes.