South African-born batsman Keaton Jennings scored a century on his debut as England made a strong start Thursday to their must-win fourth Test against India, reaching 196-2 at tea.

The left-hander, who switched allegiance to England to further his international career, was batting on 103 when the break was called in Mumbai, sharing the crease with Moeen Ali on 25.

Jennings was almost caught on zero runs and took until the 12th ball to get off the mark, but when he did there was no stopping the tall opener.

Jennings put on a partnership of 99 with captain Alastair Cook before the skipper was stumped on 46 by wicketkeeper Parthiv Patel after swinging at a Ravindra Jadeja delivery.

Joe Root came in and could only make 21 as he was caught at slip by Indian captain Virat Kohli off a spinning Ravichandran Ashwin delivery.

But Jennings, who was only called up to the squad after Haseeb Hameed was injured in the third Test, grew increasingly confident in the middle with an array of exemplary shot-making.

He brought up his ton mid-way through the afternoon session off his 186th ball with a four from an audacious reverse sweep, his third of the day.

Jennings -- who was born in Johannesburg and captained the South African under-19 team -- hit 12 fours during his century.

He became the latest South African-born English cricketer to score a ton on their international Test debut.

Andrew Strauss and Matt Prior both made centuries in their first outings while Jonathan Trott reached three figures in the second innings of his Test debut.

Jennings, whose mother is English, moved to England in 2011 after leaving school, committing himself to four years there so he could become eligible to play for the national side.

Jennings, whose father Ray played for South Africa during the apartheid era and is a former Proteas coaach, decided to switch allegiance to further his career in a similar move to Kevin Pietersen in the early 2000s.

Players who were born abroad are eligible to play for England after spending four years in English county cricket, a policy that has attracted controversy in some quarters.

England trail 2-0 in the five-match series and anything less than a victory would see India seal the contest.

Umpire Paul Reiffel received treatment and was replaced on the field after a stray ball thrown by an Indian fielder hit him on the back of the head and knocked him over.

Source: AFP