Kusal Mendis made a lively 87 off 83 balls to put tourists Sri Lanka in the driving seat at 305-6 after the opening day of the first Test against New Zealand on Thursday.

Black Caps captain Tim Southee won the toss in Christchurch, where conditions were ripe for his attack to strike, but instead it was Sri Lanka's band of classy batsmen who dominated.

Batting first on a green wicket, Sri Lanka quickly lost opener Oshada Fernando for 13.

It was heavily overcast and the ground floodlights were on, but despite the early wicket, Sri Lanka's second-wicket pair of Dimuth Karunaratne and Mendis were unfazed.

They cracked a rollicking 137 in 27 overs, with Mendis belting 16 boundaries while Karunaratne contributed 50 off 87.

When they fell in quick succession, Angelo Mathews and Dinesh Chandimal put on 82 for the fourth wicket to lift Sri Lanka to 233-4.

When conditions were at their peak for fast bowlers, Mendis and Karunaratne raced along at nearly five an over to reach 120-1, assisted by several inside edges and top edges to the boundary.

New Zealand seamer Neil Wagner, in particular, came in for some harsh treatment.

The quick bowler was taken out of the attack after his three overs cost 30 runs.

Mendis rode his luck to reach his 16th Test fifty off just 40 balls.

He was looking for his eighth Test century and the score had reached 151 when he was trapped in front by Southee for 87 to end a sparkling innings.

In the following over, with no addition to the total, Karunaratne followed, caught at second slip for 50 by Tom Latham to give Matt Henry his first wicket.

New Zealand were unable to cash in on having two new batsmen at the crease.

Mathews and Chandimal faced two overs before the drinks break and then had to start all over again when a brief shower delayed the resumption by 15 minutes.

Chandimal reached 39 before he was eventually dismissed to give Southee a brief moment of celebration.

He was the New Zealand captain's 362nd Test wicket, moving him past Daniel Vettori to second behind Richard Hadlee (431) on the list of New Zealand's top Test wicket-takers.

It also gave him the record for the most wickets across all three formats by a New Zealand bowler with 706, one more than Vettori.

Not to be outdone on the record front, Mathews drove Matt Henry to mid-on for two to reach 7,000 Test runs but he barely had time to acknowledge the achievement before he was dismissed on the next ball for 47.