"What had been a Quidditch match turned swiftly into a human versus tree battle...." (Pm)
The International Wizarding Order of Merit was awarded to Ivan Popa of Romania following the Attack of the Killer Forest at the Quidditch World Cup final of 1809 (Pm).
Popa worked to save lives of participants and spectators at the tournament after his teammate Niko Nenad set a nearby forest on a fiery rampage that lasted seven hours (Pm).
The Order of Merit in Britain is an honorific award given at the discretion of the reigning sovereign (Wikipedia).
We don't know what ranking or relationship is between the International Wizarding Order of Merit and the Order of Merlin.
From the Web
Writing by J.K. Rowling on Pottermore: History of the Quidditch World Cup
Screenshots of the original Daily Prophet coverage of the 2014 Quidditch World Cup on Pottermore: Imgur archive