Half centuries from Colin de Grandhomme and B J Watling gave New Zealand a first-innings lead of 138 against Sri Lanka on the fourth day of the second and final Test in Colombo on Sunday.
The touring side, who need a series-levelling win after Sri Lanka won the opener in Galle, reached 382 for five wickets on another rain-interrupted day.
Watling was unbeaten on 81 while de Grandhomme was 83 not out after a blistering knock with his side needing quick runs to set Sri Lanka a target on the final day.
After rain allowed just 66 overs of play on the first two days of the match, the start of the fourth day was also delayed due to wet weather and eventually only 48 overs could be bowled on Sunday.
Overnight centurion Tom Latham and Watling continued accumulating runs with ease and took their side past Sri Lanka's first-innings total of 244.
The pair added 143 for the fifth wicket for the Black Caps before Latham was finally out leg before for 154, giving off-spinner Dilruwan Perera his third wicket.
There was, however, no respite for the hosts' bowlers as all-rounder De Grandhomme went on the attack, hitting five sixes and an equal number of fours in his 75-ball knock.
De Grandhomme and Watling added 113 for the unbroken sixth wicket, giving their side hopes of victory.
Sri Lanka did not have regular captain Dimuth Karunaratne on the field after he suffered a small tear in his quadriceps while fielding on Saturday.
Former captain Angelo Mathews led the side in the absence of Karunaratne, who will be unable to open the innings and bat higher than number seven in Sri Lanka's second innings.