worked his way back to fitness to take part in New Zealand's tour of South Africa in November–December 2007. Called into the test side, Mills was forced to withdraw from the second and final Test due to a stomach bug. Coming fresh into the three match one day series, Mills was the pick of the New Zealand bowlers in all three matches, taking career best figures of 5/25 in the series opener. Despite New Zealand losing the series 2–1, Mills was named man of the series. Due in part of the absence of Shane Bond, who signed to play in the Indian Cricket League, and Mills' continued good form, he maintained his place in the ODI side. Mills became a frontline bowler for New Zealand in limited-overs matches from 2008 in and was groomed to fill the void left by Bond. During a test match against England in March 2008, he ran through the English top order with his spell of 4/16 which was also his career best test figures. His bowling helped the home side New Zealand to a comfortable crushing win by 188 runs. He dismissed Alastair Cook, Michael Vaughan, Andrew Strauss and Kevin Pietersen within his first seven overs of his spell on the final day of the test match whereas England were given a brisk target of 300. He was selected for New Zealand's 2009 ICC World Twenty20 campaign which was also his maiden appearance in a T20 World Cup. He was also a member of the New Zealand side which emerged as runners-up in the 2009 ICC Champions Trophy Final, after losing to Australia in South Africa. He achieved his highest career ODI ranking in 2009 as he was ranked as no 1 bowler in the ICC rankings for bowlers in ODIs after taking nine wickets against Australia in the 2008-09 Chappell-Hadlee Trophy and for his performances during the 2009 ICC Champions Trophy where he ended up as the leading wicket-taker for New Zealand with nine scalps in five matches. He was selected to the New Zealand squad for the 2011 Cricket World Cup as an injury replacement for Hamish Bennett. However, after featuring in just three group stage matches he was ruled out of the remainder of the 2011 World Cup tournament due to an injury. He sustained a quadriceps strain during a group stage match against Canada and was subsequently replaced by Andy