ST LUCIA: Centuries by India middle-order batsmen Ravichandran Ashwin and Wriddhiman Saha could not prevent West Indies from marginally gaining the upper hand on day two of the third test in St Lucia on Wednesday.

All-rounder Ashwin (118) and wicketkeeper Saha (104) shared in a sixth-wicket stand of 213 runs, creating history by becoming the first India number six and number seven batsmen to score a century in the same innings.

It was also Saha's first test ton, and the second-highest sixth-wicket partnership by India in an away test.

But after the India tail crumbled and the visitors were all out for 353 -- West Indies claiming the final five wickets for 14 runs -- the home team advanced to 107 for one wicket at stumps in their first innings, 246 runs behind at the Darren Sammy Stadium in Gros Islet.

Lokesh Rahul had a busy afternoon in the field for India, dropping Leon Johnson at third slip when the West Indies opener was on four.

But Rahul later made amends when he ran out Johnson for 23 with a direct hit from mid-wicket. Kraigg Brathwaite (53) and Darren Bravo (18) were unbeaten at stumps on a pitch that offered little assistance to the bowlers.

There was a scary moment late in the day when Rohit Sharma, fielding at short leg for India, was struck in the helmet by a Bravo sweep.

Play was halted for four minutes as an ice pack was applied to the back of Sharma's head, but he did not appear to incur serious injury, perhaps thanks to the padded wing on his helmet.

Earlier, Ashwin continued his outstanding form with his second century in three innings this series, bringing up his 100 in style by hoisting off-spinner Roston Chase over mid-wicket for six.

Teeanage fast bowler Alzarri Joseph (3-69) enjoyed a promising test debut for the Windies, breaking the Ashwin-Saha partnership when he had Saha caught behind, a day after claiming the prized scalp of India captain Virat Kohli.

And fellow paceman Miguel Cummins, in his second test, claimed 3-54, including the wicket of Ashwin, caught fending a short ball to backward point.

India lead the four-test series 1-0 after winning the opener at North Sound on Antigua and drawing the second match at Kingston.