Tea New Zealand 347 and 274 for 4 (Williamson 123*, Mitchell 18*) lead England 143 (Henry 4-48, Santner 3-7, O'Rourke 3-33) by 478 runs

Having reached fifty just before the close of the second day with his side already 340 runs ahead, Willamson pressed on through an extended session, bringing up his 33rd Test  century - and seventh at Seddon Park - with a thunderous six down the ground.

At the break he was unbeaten on 123 with Daryl Mitchell on 18 not out. Not only was New Zealand's mounting lead a concern for the tourists, but Stokes pulled up mid-over clutching the same left hamstring he injured during the Hundred in August.

It was a typically composed innings from Williamson, though not without its chances.

He survived a close lbw decision on umpire's call off Brydon Carse while on 73 with replays showing the ball was ever so close to clipping the bails at the top of leg stump.

He was also dropped by Ollie Pope on 86 when his attempted pull off Stokes made its way into the glove, but the keeper, leaping a long way down the leg side, couldn't hold on.

Then, on 106, he edged fine of second slip where Harry Brook wrongly anticipated the shot off Shoaib Bashir and inadvertently created space for the ball to squeeze through.

But Williamson marshalled the innings expertly when New Zealand resumed on 136 for 3 after heavy rain wiped out the morning session.

They added 50 runs in the first 19 overs of the day as Rachin Ravindra exercised a more cautious approach than that which had led to his downfall earlier in the series, unnecessarily chasing the ball outside off stump, while Williamson steadily accumulated.

Even as the chatter from England sought to remind him of this, Ravindra bided his time expertly before playing some shots from midway through the afternoon, including four off the Stokes short ball which caused the England skipper to pull up injured and limp from the field immediately.

Jacob Bethell completed the over with his left-arm spin and bowled just one more over, conceding the straight six that brought up Williamson's century followed by four more down the ground two balls later.

In the meantime, Ravindra had dispatched offspinner Shoaib Bashir for four through backward point and six over deep midwicket to move into the 40s.

But Ravindra couldn't follow Williamson to a landmark score - he fell to a leading edge off Matthew Potts, which was snaffled by Carse, who had given him an earful after conceding Ravindra's first four, dispatched through midwicket, earlier in the innings.