Sri Lanka face a mountainous task to avoid defeat in the second Test against New Zealand after collapsing for 164 in their first innings on Sunday and being forced to follow-on.
The tourists were 12 without loss in their second innings at tea on day three, still trailing by 404 runs and needing a massive turnaround at Wellington's Basin Reserve to prevent the hosts sweeping a 2-0 series win.
Sri Lanka's tail succumbed rapidly in the second session as the last six wickets tumbled for 50 runs in the space of 15.1 overs.
What looked like a docile wicket as the Black Caps coasted to 580-4 declared suddenly seemed treacherous as the Sri Lankans succumbed to a succession of rash shots.
Only three reached double figures, including captain Dimuth Karunaratne, who was the ninth man out for 89.
The opener had looked to be digging the visitors out of a deep hole when he and Dinesh Chandimal put on 80 for the fifth wicket after the loss of two wickets in the day's opening half-hour reduced them to 34-4.
However, Chandimal was stumped for 34 off Michael Bracewell after charging down the track soon after tea, sparking the slump.
Offspinner Bracewell removed Dhananjaya de Silva in his next over and ultimately removed Karunaratne when he hit out, to finish with 3-50.
Seamer Matt Henry claimed 3-44, including wicketkeeper Nishan Madushka, who scored a rapid 19 on his Test debut.
Kasun Rajitha was run out and Asitha Fernando was the last wicket to fall, both for ducks, as Sri Lanka ceded a 416-run advantage to New Zealand on the first innings.
Captain Tim Southee had no hesitation asking Sri Lanka to bat again, even though that tactic backfired less than a month ago when England enforced the follow-on midway through the second Test against the Black Caps at the Basin Reserve.
New Zealand went on to win, becoming just the fourth team in Tests to prevail after following-on.
Karunaratne was to resume on seven not out and Oshada Fernando on five not out after the opening pair saw off the last nine overs before tea.