In the A-League grand final, Fyfe played an important role in defending Sydney's 1–0 lead over the Central Coast Mariners, having replaced injured Mark Rudan with 20 minutes remaining.

In the 2006–07 season, Fyfe was shifted to a wide defensive role by new coach Terry Butcher, who opted to play Mark Milligan in midfield rather than his usual right back position.

The impact of the move was immediately apparent with Fyfe, goal-less in the previous season, scoring the winning goal against Central Coast in the opening round and netting again in the 3–2 loss to Melbourne Victory a week later.

Strong performances led to another call up to the national team, included in the A-League-based Australian side for the 2007 Asian Cup qualifier against Kuwait on 16 August 2006, but again did not make an appearance.

During the Pan-Pacific Championship Iain played his 100th competitive game against Major League Soccer Glamour team Los Angeles Galaxy.

In November 2016, Fyfe signed a short-term deal to return to the A-League with Newcastle Jets as an injury replacement for Daniel Mullen, joining from South Australian club Campbelltown City.

[14] Fyfe started his career in 1999, joining a talent identification program at the South Australian Sports Institute, and was soon exposed to the international football stage.

He was selected for the Australian U17 side in qualifying matches for the 1999 FIFA U-17 World Championship and retained his place in the Joeys squad for the final tournament in New Zealand.