India waltz into World Cup final after Shami seven-for and centuries from Iyer and Kohli

India 397 for 4 (Kohli 117, Iyer 105, Gill 80*, Southee 3-100) beat New Zealand 327 (Mitchell 134, Williamson 69, Shami 7-57) by 70 runs

New Zealand had no business giving India the nervous moments they did in a defence of 397 but India eventually made mockery of the supposed knockout pressure as they waltzed into the final, now one step from possibly the most dominant World Cup campaign. The average victory margin for them now is 175 runs, 6.4 wickets and 64.4 balls remaining. Australia's 2007 triumph was 147.67 runs, eight wickets and 89.2 balls remaining.

In doing so, Virat Kohli went to a mindboggling 50th ODI hundred in front of his wife, in front of the man he went past, Sachin Tendulkar, and at a ground where the torch was metaphorically passed 12 years ago when he carried Tendulkar on his shoulders. Shreyas Iyer scored a second straight century, at 67 balls, the third-fastest by an Indian in a World Cup, all three in this edition.

One of those three centuries belongs to the selfless Rohit Sharma, who set India up with yet another blazing start of 47 off 29, the ninth time this year that he got out in 40s, 80s or 90s, the joint-highest number for a calendar year.

It is no surprise that India scored the highest total in a World Cup knockout match, which was always going to be plenty at a ground that has shown the most variance in bowling friendliness from afternoon to evening this tournament. As expected, it went from no swing or seam in the afternoon to appreciable movement in the air and off the surface, followed by surprising prodigious turn and no dew, but Daryl Mitchell scored a scarcely believable 134 off 119 only for Mohammed Shami to thwart them with 7 for 57.

You can't begrudge India any of the breaks they got with the conditions: this was only the second toss they had won in nine knockout matches in limited-overs World Cups since the Mohali semi-final against Pakistan in 2011. On a used pitch, that advantage was negated a little as it would mean marginally more assistance for the slower bowlers during the afternoon and marginally less assistance for the quicks under lights.

However, Rohit converted this marginally smaller advantage into a proper headstart even before spectators had settled in. He already has the most runs, highest strike rate, highest average, most sixes, most fours in the powerplays this World Cup. In a semi-final on a slow pitch, it wouldn't be unreasonable if he have himself a couple of sighters, but he started going in the first over, flamboyantly flicking a length ball over midwicket in order to create his own momentum into the shot.

As early as the third over, Trent Boult was around the wicket, suggesting no movement for the fast bowlers. To Boult's first ball from that angle, Rohit danced down the wicket and lofted over mid-off for his first six of the day. He would add three more in his brief innings to go two each past Chris Gayle's record for most World Cup sixes and most in a single World Cup: 49 and 26.

India's top five now average more than any side in a single World Cup, but it is in sticking to their roles that they have been the most impressive. Rohit's job has been to maximise; accumulation can be left to Shuman Gill and Kohli. Rohit's personal score doesn't matter. He fell on 47, trying to hit a fifth six but was undone by a Tim Southee slower ball.

Twelve years after Kohli carried Tendulkar on his shoulders to thank him for carrying the team, Gill, heir apparent to Kohli, took on the aggressor's role to allow Kohli time to get into his work. Now these are only relative terms because 29 off 39 is not a bad start knowing how Kohli can accelerate, but in the same time Gill added 59 off 45. However, with a century there for the taking, Gill retired-hurt with what looked like cramps, presumably so as to not jeopardise his participation in the final.

For New Zealand, though, this retirement was like jumping from the pan into the fire. Iyer batted with ferocity and touch, taking down Rachin Ravindra after just six sighters. Now in the second half of the innings, Kohli, too, began to up his intent. He went after the returning quicks, Boult and Southee. Iyer made sure they had to take the part-timers out of the attack.

The only reason Iyer didn't get the fastest World Cup century for India was a maiden bowled by Mitchell Santner in the 35th over. Santner was the only bowler who held his own, going for just 51 in his 10.

India took 110 off the last 10 overs with KL Rahul's 39 off 20 providing the finishing touches. You wouldn't have guessed at that point that India would need all these runs, which makes all the starts from Rohit and the intent the new team management has insisted on even more crucial.

Those extra runs provide a cushion if the bowlers have half an off day. Jasprit Bumrah had just that kind of a start that proves he is human: 22 runs in three overs, plenty of width, a set of five wides. First-change Shami, though, emerged as the nightmare for the batters. Immediately around the wicket, he toyed with the two left-hand openers, nibbling it just enough to have them caught at the wicket in his first two overs.

It gave India some relief and the freedom to introduce Ravindra Jadeja early should there be dew later. Both the spinners found turn from the pitch, but incredibly, Mitchell kept hitting them down the ground, including the biggest six of the tournament. Mitchell and Kane Williamson added 181 for the third wicket, a catch went down, a possible run out was missed as Rahul broke the wicket too soon, faces grew tense, meetings got longer. And when the returning Bumrah was off-driven for six by Mitchell, you knew things had got serious.

Shami, though, returned with a double-strike: a slower ball to have Williamson caught at deep square leg, and an absolute peach to seam in and hit Tom Latham's kneeroll second ball. With Glenn Phillips in, India could go back to the spinners and mount the asking-rate pressure. It went past 12 in the 37th over, and with Mitchell cramping and India smartly keeping the ball out of his reach, it just became a losing battle for New Zealand.

Shami came back to take three deserving wickets in the end, becoming the quickest to 50 wickets in World Cups, moving to most five-fors and also registering India's best figures in the tournament.