Lomu was set to feature for the North Shore side in the 2005 NPC after his recovery from a kidney transplant.
But a series of injuries saw him miss the entire season, with an attempted comeback at Cardiff also stifled.
But he finally returned as Harbour completed a fourth win in four games.
The former All Black winger told Sky Sports: "It's just good to get some time out there and not get injured, and get some time on the field, in New Zealand."
Allan Pollock's team remain two points adrift of neighbours Auckland in Pool A, after the provincial champions claimed a bonus point from their 45-27 win over Bay of Plenty at Eden Park.
The hosts came back from a 27-6 deficit with 39 unanswered points to also tally a fourth straight victory.
Taranaki scored their first Pool A win with a 17-12 defeat of neighbouring Manawatu in the group's other game.
Former Leinster fly-half David Holwell led Northland to their first provincial victory in three seasons at Mount Smart Stadium.
Holwell, Jake Paringatai and Josh Levi scored tries as the Taniwhas claimed a 21-17 victory over Counties-Manukau Steelers, their first in 30 attempts.
Skipper Holwell said: "It's been a long time and something we haven't been proud of.
"It's been a monkey on our back for the last couple of seasons and it's good to have got rid of it.
"It'll give the boys a lot of confidence and a lot of self-belief. It's great we can deliver it for out fans."
Otago's All Blacks fly-half Nick Evans scored a last-gasp in a 24-21 win over Waikato at Carisbrook.
Otago moved back to the top of Pool B after Canterbury's successful Ranfurly Shield defence against Southland.
Rob Penney's side scored a 24-7 win over the Stags at Jade Stadium.