Debutant Shreyas Iyer followed his first-innings hundred with a crucial 65 to help India stretch their overall lead to 216 runs against New Zealand in the opening test in Kanpur on Sunday.

India lost four wickets in the morning session on day four to slump to 51-5 but Iyer came to their rescue again before falling to Tim Southee on the stroke of tea with India on 167-7.

Wriddhiman Saha, who could not keep wicket on Saturday with a stiff neck, was batting on 22 at the other end.

Earlier, Southee (3-48) struck twice in three balls in the morning session as New Zealand blew away India's top order after India had resumed on 14-1.

Kyle Jamieson (3-26) conceded a couple of early boundaries before he dismissed Cheteshwar Pujara, who made 22, to open the flood gates.

Left-arm spinner Ajaz Patel further pegged back India when he trapped home captain Ajinkya Rahane leg before wicket for four with an arm-ball that kept low.

Southee then twisted the knife by removing opener Mayank Agarwal, caught in the slip, and Ravindra Jadeja, trapped lbw, in a two-wicket maiden over to reduce India to 51-5.

Iyer and Ravichandran Ashwin, who made 32, not only arrested the slide, but also scored briskly to put the pressure back on New Zealand.

After Ashwin departed, Saha slog-swept spinner Will Somerville for a six, while Iyer smashed Patel over his head for a similar result.

Iyer's fine knock came to an end when he gloved a Southee delivery he was trying to pull.

Mumbai hosts the second and final test from Friday.