The second episode was watched by 1.28 million viewers on July 20, a loss of 650,000 viewers from the debut.
However, pundits have said many viewers are watching later ''on demand'' and the bleak wintry miniseries would have been better served if it was broadcast during the northern hemisphere's winter, not during the summer months on Saturday nights.
Nevertheless, columnist and television critic Caitlin Moran said Jane Campion's eight Emmy award-nominated thriller was ''currently knocking everything else out of the ballpark'' in her review before the third episode on BBC Two last Saturday.
Ms Moran and several critics praise the ''astonishing array of unique and odd female characters, unlike any you've seen before''.
Celebrities have weighed in with their praise, including Lena Dunham, writer and star of the HBO drama Girls, who tweeted Top of the Lake ''is the best thing on television''.
Ellie Danger wrote one of the most insightful pieces about the series for Organised Freedom.
The splitting of men and women is down very clear lines and ''the real evil in Top of the Lake is the patriarchy'', Danger said.
''There is no place . . . where women are safe; violation is a constant threat.
''When order is restored . . . it is done by a woman in complete control of her faculties who is doing her job and she is doing it well.''
Serena Davies, of the Daily Telegraph, was hooked on the three ''romances'' unfolding in the third episode, from ''sweetness'', to ''uncomfortable'' to ''electrifying''.
Campion and co-director Garth Davis are ''clever'' for creating characters the audience cares about, Davies said.
''The bad get under your skin, the good you start to love. The character studies in Top of the Lake are deeply humane, and form of one of several reasons to watch this clever, surprising programme.''
The Telegraph linked the thriller, ''filmed in the picturesque village of Glenorchy'', and The Hobbit with the 10% rise in international visitors to New Zealand in the first half of 2013, compared with the corresponding period last year.
Top of the Lake is considered an industry trailblazer by The Guardian.
Television viewers can expect to see more drama directed by an Oscar winner and set and filmed ''abroad'', as ''film-makers increasingly turn their attention to the small screen and domestic broadcasters expand their horizons worldwide'', it says.
