Team GB have eight host nation quota places available but Kruse was determined to become the first fencer to automatically qualify through the world rankings since James Williams at the Sydney Games 12 years ago.
He knew he needed to win in Denmark to avoid the zonal qualifiers, while relying on a host nation invite was his next back-up.
However, he beat key rival Ukraine's Rostyslav Hertsyk in a tough round of 16 draw, coming from 13-12 down to win 15-13.
He then eased through his quarter and semi-final before beating fellow finalist Francesco Trani in a tense sudden-death extra minute.
“I have never sweated so much blood for a World Cup point but it was worth it," said Kruse, who finished eighth in Athens, the best performance by a British fencer since 1964 - and lost one round earlier in Beijing.
Kruse's qualification will ease the pressure on recently-appointed performance director Alex Newton, drafted in after last year's European Championships in Sheffield where the home fencers failed to perform.
"We were always confident that Richard would secure qualification here or at the zonal qualifiers but it's great to have it in the bag," she said.
"This is the first time we have qualified though world rankings since before Sydney, it's a great achievement."