Play was suspended in the final round in Kuala Lumpur with the last group on the 18th green when a thunderstorm hit Saujana Golf and Country Club.
Elvira, who was a shot behind Hend at the time, was disturbed by a clap of thunder as he played his pitch to the closing par five and came up around 30 feet short of the flag.
Moments later play was suspended and when it eventually resumed after a delay of an hour and 40 minutes, Elvira holed his putt for an unlikely birdie to join Hend on 15 under par.
— The European Tour (@EuropeanTour) March 24, 2019
Hend was left with a putt to win from a similar distance but could not convert and the two players went into a sudden-death play-off to decide the winner.
After being allowed a short warm-up on the 10th tee, the leading duo returned to the 18th and Hend enjoyed a slice of luck when his drive hit the base of a tree and rebounded back into the fairway.
Elvira found a bunker off the tee and, after laying up, hit a mediocre approach and was unable to make birdie, but Hend got up and down from a greenside bunker to seal an eventful victory.
Hend, who carded back-to-back rounds of 67 over the weekend, said: "What a putt by Nacho, unbelievable. If I was to go out there and hit that putt, you'd probably hole it one in 10 times. It was an amazing putt and the situation he holed it in was awesome. All credit to him.
"I had a bit of luck on the play-off hole to win, you need luck to win and I was fortunate to have the luck today. Unfortunately for Nacho he was against the luck but his time's going to come, he's a great player and he's going to win."
Hend began the final round three shots behind Elvira, but raced to the turn in 31 and moved two shots clear with another birdie on the 13th, before Elvira halved his deficit with a birdie on the 16th.
Heavy rain began to fall with the last group on the 18th fairway and after Hend
hit his third shot to around 30 feet, the thunder arrived at a most inopportune moment, much to the annoyance of Elvira's fellow Spaniard Pablo Larrazabal, who criticised the European Tour for not suspending play sooner.
Elvira, who is yet to win on the European Tour, said: "It was thunder in a bad moment to be honest, but the Gods give me one back.
"I think I played great all week, I'm very happy with that. I tried to give it all on the 18th hole (in the play-off). I just missed my drive a little bit and gave myself little chance to make birdie but I'm happy overall."
Thailand's Jazz Janewattananond finished two shots outside the play-off in outright third, with four-time major champion Ernie Els three strokes further back in a tie for seventh, the 300th top 10 of his career.
The 49-year-old South African is the first player to reach the milestone since the inception of the world rankings in 1986.