In 1989, Lomax, alongside his three brothers (Arnold, Tony and
David), played for Wainuiomata in their
Wellington Rugby League Grand Final win over Upper Hutt. In 1990, Wainuiomata won the Wellington Rugby League and the national
Lion Red Cup competitions. That year, he represented the
New Zealand Māori team against
Great Britain. He later played at the
1992 Pacific Cup. In 1992, Lomax and his three brothers represented Wellington against
Bay of Plenty. All four brothers later played in the Lions 25–18 national Grand Final win over the
Northcote Tigers. In 1993, he was invited to be part of an Auckland Invitational XIII side that drew 16-all with the
Balmain Tigers.
Canberra Raiders In 1993, Lomax moved to
Australia, joining the
Canberra Raiders in the
NSWRL Premiership. In Round 1 of the
1993 NSWRL season, he made his first grade debut in Canberra's 8–22 loss to the
St George Dragons. In his debut season for the club, he played 20 games, starting all 20 at . In June 1993, he made his debut for
New Zealand, playing in their three-game series against
Australia. At the end of the year, he was selected to go on the
1993 New Zealand rugby league tour of Great Britain and France, playing in all five
test matches. In 1994, Lomax played 23 games for the Raiders and won the club's
Player of the Year award but missed their
Grand Final win over the
Canterbury-Bankstown Bulldogs due to suspension. A week earlier, he was sent off and charged for a high shot on
Billy Moore in the side's 22–9
preliminary final win over the
North Sydney Bears. In 1995, he played just 10 games for the Raiders but captained New Zealand for the first time in their mid-season series against
France. On 23 June 1995, he captained New Zealand for the third and final time in an 8–26 loss to Australia. In October 1995, he represented New Zealand at the
1995 Rugby League World Cup, playing one game. In Round 12 of the
1996 ARL season, Lomax collected
Parramatta's
Adam Ritson with a high tackle, knocking him out. Following the incident, a routine scan discovered that Ritson had a life-threatening brain cyst, from which he would never fully recover, ending his career.
North Queensland Cowboys In 1997, Lomax signed with the
North Queensland Cowboys, joining his former Raiders' head coach
Tim Sheens at the club. In his first season at the Cowboys, he played 15 games, missing three weeks due to suspension. That year, he became the club's first New Zealand international when he played in the Kiwis' 30–12 win over Australia. In 1998, he took over as captain of the Cowboys and won the club's Player of the Year award. On 24 April 1998, he started at prop for the Kiwis in their 22–16
ANZAC Test win over
Australia, his last game for his country. In 1999, Lomax played just eight NRL games due to injury.
Melbourne Storm In 2000, Lomax moved to the
Melbourne Storm, playing just three games for the club before retiring at the end of the season. ==Achievements and accolades==