While the team endured a difficult campaign, Vainikolo stood out as an offensive weapon, finishing third in the competition with six tries, including several of the highlight-reel variety.

In the 2009 Super 14 season, Vainikolo struggled to repeat his first-year success, scoring only two tries and facing increased criticism for his defensive play, splitting starts with the more reliable Kendrick Lynn.

Concerns about his all-around game and poor form during the 2010 ITM Cup saw Vainikolo left off the Highlanders main squad for the 2011 Super 15 season, although he was included in the team's wider training group.

On the conclusion of Tonga's participation at the 2011 Rugby World Cup, Vainikolo joined the Irish province Connacht for the 2011–2012 season.

He scored a vital try against Irish Rivals Leinster Rugby, in a Pro12 derby to help Connacht gain a 34–6 win over the European champions.

[11] Fetu'u was called into the Tongan 2012 IRB Pacific Nations Cup squad, which was being hosted by Japan and Fiji in June 2012.