Lunt, a member of the Rhinos' Grand Final-winning team last October while out on loan, continued his exceptional form on his return to the Giants by taking his try tally for the year to 18.
Huddersfield's other hero was skipper Danny Brough, who pulled all the strings and kicked six goals from seven attempts to keep his side on the heels of leaders Wigan.
Scrum-half Luke Robinson crossed over for the opening try, while Aaron Murphy, Brett Ferres, Leroy Cudjoe and Scott Grix also scored a try apiece for the Giants as Liam Sutcliffe went over in each half for the Rhinos, either side of Ben Jones-Bishop's effort. Zak Hardaker added the extras for the visitors.
Wakefield captain Danny Kirmond grabbed an excellent hat-trick as the Wildcats celebrated their 140th anniversary in style with a convincing 46-14 victory over an under-strength London Broncos side in front of a packed Rapid Solicitors Stadium.
Roared on by 8,203 fans, the hosts set the tone with tries by Peter Fox and Richard Mathers from close range inside the first 12 minutes. Second-rower Kirmond then touched down twice - once either side of a Paul Sykes effort - with Lee Smith converting all five first-half tries.
The Broncos hit back before the break when Liam Colbon collected an excellent offload from debutant Harry Little. Kieran Dixon's double after the interval closed the Broncos' deficit to 16 points, but Kirmond dived over for his treble after the hour mark and Frankie Mariano and Kyle Wood added further late scores for the Wildcats.
And two tries from former Bradford winger Patrick Ah Van capped a spirited fight-back and helped give Widnes their first victory at Odsal for almost 23 years as they claimed a 32-28 triumph.
Ah Van struck twice in less than three minutes near the end to give the Vikings victory in a game in which they had trailed 18-4 midway through the first half. It was 13th time lucky as the Cheshire side had gained just a point - a 25-25 draw in 2005 - from their previous dozen visits to the West Yorkshire venue dating back to September 1990.
Rhys Hanbury and Stefan Marsh also claimed two tries apiece as Widnes wiped away the memories of a string of near misses to claim their second away win of the season and Jack Owens added the extras.
Adam Sidlow, Keith Lulia, James Donaldson, Elliot Kear and Michael Platt crossed over for the Bulls with Luke Gale on target with four conversions.