The 22-year-old came from 3-1 down to win nine of the last 11 frames against 2005 world champion Murphy.
Brecel, who shocked Ronnie O'Sullivan in the quarter-finals, is the first player from continental Europe to win a ranking title and he pockets £150,000.
Victory moves him from 27th to 15th in the world rankings.
Brecel is now up to 11th in the race to make the Masters in January, with the top 16 players qualifying.
Murphy, 35, wins £75,000 and climbs from eighth to fifth in the rankings.
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Belgium's Luca Brecel won his first ranking tournament as he beat England's Shaun Murphy 10-5 in the final of the China Championship in Guangzhou.