Their father Peter - who watched the race with mum Jackie and sisters Casey and Jordan - said the twins had a unique approach to racing.
"They run as one - they don't really care which one wins, as long as no-one else beats them," Peter Nicholson said.
Mount Maunganui Intermediate student Lucy Bartlett equaled the Year 7 girls record with a slick 11min 24sec time, edging Paris Carroll (Heaton) by 8secs with Raroa Normal's Sarah Hay another 4secs back.
Bartlett was also a strong swimmer, netballer and surf lifesaver. Mum Jackie Read was a former New Zealand surf lifesaving representative, while dad Scott Bartlett was an Australian representative and former New Zealand coach.
Although her aquatic ability is impressive, Bartlett Jnr targeted the cross country this week at the AIMS Games.
"That was such a hard race but I wouldn't do it if I didn't absolutely love it," she said.
One of the smallest of the 275 schools at AIMS this week - Tauranga's Waldorf School in Welcome Bay - picked up its second gold in as many years with Maia Flint adding the Year 8 crown to the Year 7 title she won last year.
It was much tougher this year for the slim Flint, however, with Rotorua's Hannah Gapes closing to within 2secs in a storming finish. The pair had regularly dueled over recent years, although Flint's tactics of starting fast usually pay off.
"I don't have much of a sprint on me so I try and get out to a good lead and make them chase me," she said.
Gapes had Wednesday's multisport to look forward to, having spent plenty of time mountain biking and kayaking on Rotorua's world-class trails and lakes lately.
Tauranga Intermediate's Benji McManus capped the local dominance, erasing the 10-year-old Year 8 boys record set by Fairfield's Mohammed Ali in 2006.
McManus was 5secs quicker than the 10min 10sec record, with schoolmate Callum Jeffries and last year's Year 7 champion Zane Powell also edging under the old record. Both recorded 10:07, with Jeffries awarded second by 0.22secs over the 3km.
"I got passed at the big hill and I knew I just had to put my head down and not stop," Mcmanus said. "It was a great feeling to get to the straight and look around and know I'd won it."
McManus picked up three golds on the opening day, helping Tauranga Intermediate win the Year 8 boys teams race, then anchoring his school's win in the 15km event-ending relay, from Otumoetai, with Somerville Intermediate third.
Sailing also got underway on the first of six action-packed days at AIMS, with most of the 21 codes beginning on Monday.
Results:
Year 7:
Girls: Lucy Bartlett (Mt Maunganui) 11:24 1, Paris Carroll (Heaton) 11:32 2, Sarah Hay (Raroa Normal) 11:36 3, Katelyn Sceats (Chilton St James) 11:44 4, Isla Westlake (Murrays Bay) 11:55.
Boys: Daniel Nicholson (Katikati College) 9:56 1, Sean Nicholson (Katikati College) 10:07 2, Mathijs Wetzels (Te Kowhai School) 10:16 3, Joe Morgan (Peachgrove) 10:36 4, Liam Davis (Cambridge Middle School) 10:43.
Year 8:
Girls: Maia Flint (Tauranga Waldorf School) 11:01 1, Hannah Gapes (John Paul College) 11:03 2, Isabella Richardson (St Cuthbert's College) 11:10 3, Neve Moulai (Heaton) 11:19 4, Arabella White (Diocesan) 11:23 5.
Boys: Benjamin McManus (Tauranga) 10:05 1, Callum Jeffries (Tauranga) 10:07 2, Zane Powell (Somerville) 10:07 3, Luke Clements (Kamo) 10:14 4, Conner Woolston (Waitakaruru School) 10:19 5.
Team relay: Tauranga Intermediate 41:50 1, Otumoetai Intermediate 41:58 2, Somerville Intermediate 43:33 3, Bucklands Beach Intermediate 43:51 4, Reremoana Primary School 44:04 5.
