Root, who himself returned to form with a century against India in Ranchi last month, is the main beneficiary of Smith's slip in form since taking over from David Warner as Australia's new Test opener, which culminated in scores of 31 and 0 in the first Test against New Zealand in Wellington last week.

Head's slide means a rise in the rankings for three India batters, with Yashaswi Jaiswal breaking into the top ten for the first time, having made 665 runs and counting in the ongoing series against England. Rohit Sharma is one place behind him at No.11, while Virat Kohli climbs one place to No.8 despite not having featured in the series following the recent birth of his child.

Cameron Green has been the week's biggest climber in the batting rankings, following his match-winning 174 not out in Australia's first innings at Wellington. He is up 22 places to 23rd position, on a career-best tally of 661 points.

Williamson, on 870 points, remains comfortably ahead of Root (799) at the top of the rankings, following his formidable run of seven centuries in his last eight Tests.

On the bowling front, Nathan Lyon's 10-wicket match haul against New Zealand has lifted him two places to No.6 in the rankings, on 797 points, just two less than his career-best tally at Edgbaston last year, prior to his Ashes series-ending injury.

Glenn Phillips, New Zealand's offspinning allrounder, made significant gains on the batting and bowling fronts after making 71 and taking 5 for 45 at Wellington, while Matt Henry climbs into the top 20 for the first time after taking eight wickets in the match.

The other match to affect the rankings this week was Ireland's maiden Test victory, against Afghanistan in Abu Dhabi. Mark Adair's eight wickets in the match has moved him up 30 slots to 69th position on the bowling charts, while Andy Balbirnie, Curtis Campher, Paul Stirling and Andy McBrine all moved up into the top 100 in the batting rankings.

Hashmatullah Shahidi gained five placed to reach 81st position among the batters, while Naveed Zadran moved up 32 places to 79th among the bowlers.