Norén had trailed Hend by a shot heading into the final round but a five-under-par 65 allowed him to finish level on 17 under with Hend, who had a 66.
The pair then had to go back up the 18th and Hend hit his tee-shot towards the trees on the left but saw his ball bounce back to the fairway and only just cleared the water with his second, as Norén put his second from the fairway to 30 feet.
The Australian chipped to eight feet but Norén holed his putt for the birdie and the win.
It is the second time the Swede has won the European Masters after a previous triumph in 2009, and his second win of the year following his Scottish Open victory in July.
“It was amazing. I've never won coming from behind. I've never won a play-off on the European Tour, so it feels even more amazing,” said Norén, who took some time off earlier in the year when his partner had a baby.
“It's fantastic. I never thought it would be this good of a year.”
Norén birdied the first and a run of four straight birdies from the sixth put him two shots clear at the turn, with Hend claiming birdies at the fifth and ninth.
However, Hend fought back on the homeward stretch to force the play-off, bogeying the 11th but then managing three birdies at the next four holes.
Norén was level on the back nine and a sudden death play-off awaited after Hend got up and down from the back of the green for par at the last while his Swedish opponent could not convert a long birdie attempt.
England's Andrew Johnston finished third at 14 under par, with Lee Westwood — a wildcard pick in the Europe team for the upcoming Ryder Cup — two shots further back in fourth after finishing with a 63.
It has been a vintage year for Swedish golfers. Along with Norén's European Masters and Scottish Open victories, veteran Henrik Stenson claimed his first ever British Open back in July, as well as a silver medal at the inaugural men's Olympic golf competition in August.