Boult, Southee force SL to follow on

Having been battered and bruised on Boxing Day, the ball finally had its way in Christchurch. Trent Boult summoned swing, Tim Southee got it to seam, and Sri Lanka collapsed to 138 in reply to New Zealand's massive 441 and were forced to follow-on. Sri Lanka showed better mettle in the second innings, as Dimuth Karunaratne and Kaushal Silva shared an unbroken, opening stand of 84.

The first ball of the morning, at Angelo Mathews' gentle pace, had swung past the outside edge. The trend continued, only the tourists began their innings with 13 straight overs of Boult and Southee manipulating their length and line to suit the swing on offer. They attacked middle and off stump, moving wide of the crease every so often to create difficult angles. Sri Lanka were reduced to 15 for 3. Recovery appeared, and eventually turned out to be, impossible.

Karunaratne had the courtesy one sighter before he was put under scrutiny. Boult's fourth ball of the innings threatened to shape away, had a change of heart once it hit the pitch and jagged back to pin him in front of the stumps. A delivery that befit the occasion of Boult's 100th wicket, in only his 29th Test.

Boult's inswing was the reason for Silva's second single-figure score of 2014. The opener had got across too early and was extremely late in preventing the ball striking pad. He did challenge the umpire's leg-before decision, hoping the exaggerated swing would save him but had to accept his dismissal.

Kumar Sangakkara's mistake was in direct contrast to Silva's. His feet did not move to a teasing outswinger from Boult, especially considering the choice of shot - his favourite cover drive. Southee, at third slip, held the outside edge and Sangakkara, who had begun his innings 12 short of 12000 Test runs, was out for 6.

Southee had nothing to show for his work in the first session. He remained patient though and was rewarded when Lahiru Thirimanne drove a touch carelessly outside off in the eighth over after lunch. Four balls later, Niroshan Dickwella closed the face too early and spoon a catch to short cover. With New Zealand's skill to move the ball in the air, it almost seemed cruel that Southee got a cross-seamed delivery to misbehave.

Mathews was the only man who resisted, biding his time until the movement diminished. He pushed himself to make twos, backed himself to slam Boult into the sight-screen and willed himself to a half-century. New Zealand would have been wary of his average of 89.46 in the last 12 months and a penchant to lead the tail, but this time his team-mates barely lasted long enough to even think about offering support. Brendon McCullum was already prepping for the follow-on, having pulled Southee and Boult out of the attack with half the opposition dismissed and more than 10 overs left for tea.

In Sri Lanka's second innings, Boult and Southee were unable to reprise the same threat. Not as many deliveries demanded the two Sri Lanka openers to play, even though the ball was moving late into the final session. Silva and Karunaratne saw the side through to stumps. Both took care to play with bat and pad together and as late as possible and tried not get bogged down.

There were a few deliveries fizzing past the outside edge, the substitute fielder dropped a straightforward catch in the 12th over and another difficult chance could not be converted at point in the 27th. But they attacked as New Zealand bowled shorter with the old ball to salvage a poor day.

Things had looked just a bit better at start of play when they had dismiss New Zealand's tail in under six overs. There were no specialist batsmen left after wicketkeeper BJ Watling was lbw off what became the final delivery of Boxing Day. The final five wickets were able to contribute only 21 runs, but what happened previously and a little bit later was more than enough compensation for the home side.