When the handicap formula was applied it gave Attwell an effective throw of 84m, way higher than the formula gave Langton-Burnell from his best actual throw of 77.88m on the night.
"I wasn't expecting that," Attwell said.
"Javelin is my weakest discipline, well it was until now."
Langton-Burnell said he actually enjoyed the format of the handicap system rather than feeling dismayed when beaten by a lesser throw.
"I actually embrace the competition," Langton-Burnell said.
The Manawatu athlete is now based in Hamilton under the eye of coach Debbie Strange and his immediate focus in the upcoming Australian and New Zealand nationals.
"My other big challenge is to throw 80m to qualify for the 2018 Commonwealth Games on the Gold Coast. I'm only short distance off it."
Meanwhile, Attwell had entered five events on the night, including the Silks Audit Alan Webby 400m Handicap featuring Australian speedsters Alex Rowe and Deluca Lawson-Matthew. Rowe had easily won the 800m at the Potts Classic in Napier last Saturday and was favoured to cross the line first or second over the 400m at Wanganui.
He was only just pipped on the line by countryman Lawson-Matthew, but handicap honours went to Josh Ledger from Upper Hutt with an effective time of 45.94 after the handicap formula was applied.
Attwell finished relatively close up behind the leading bunch.
"I was pretty happy with my 400m run given the other events I competed in on a busy night. I'm studying engineering in Christchurch and training under Terry Lomax (former topline decathlete).
"My major focus is getting ready for the Australian and New Zealand nationals an d in the meantime I will compete in the high jump and high hurdles at the Capital Classic in Wellington on Friday," Attwell said.