UPDATE 3-Golf-Wolff steals show at U.S. Open, leads DeChambeau by two

* Wolff goes low despite hitting just two of 14 fairways

* Overnight leader Patrick Reed falls apart on back nine (Recasts at end of round)

MAMARONECK, N.Y., Sept 19 (Reuters) - Matthew Wolff, playing in only his second major, stole the show at an unforgiving Winged Foot with a scorching start and steady finish to grab an unlikely two-shot lead over big-hitting Bryson DeChambeau on Saturday.

Wolff, 21, began the day four shots behind overnight leader Patrick Reed but erased that deficit in seven holes en route to a five-under-par 65 that tied the low round of the week and brought him to five under overall.

"I like to go out there and do what I feel comfortable with, rip dog and see how it goes from there," said Wolff, who will look to become the first player to win the U.S. Open in his tournament debut since Francis Ouimet in 1913.

"I feel comfortable with every part of my game so I don't like to shy away from things when I'm feeling confident, and I'm probably going to do the same tomorrow."

The front nine at Winged Foot is one of the more daunting stretches in golf but a steadfast Wolff came out firing lasers at tricky pin positions and reached the turn with a blistering five-under 30 after five birdies.

Wolff, who hit just two of 14 fairways, made his lone bogey at the par-four 16th but responded in style with a birdie at the last after sticking his approach shot to 10 feet.

DeChambeau (70), who began the day one shot back of Reed, made a bogey-bogey start but leaned on his power to chase down Wolff and squandered a chance to finish within one shot of the lead when he two-putted from six-feet for a closing bogey.

Former British Open champion Louis Oosthuizen (68) was four shots back of Wolff while Hideki Matsuyama (70) and Xander Schauffele (70) were each a further shot adrift.

World number 10 Reed (77) drained a nine-foot birdie at the ninth to share the lead but fell apart over a nightmarish inward nine during which he made six bogeys and a double-bogey to fall into a share of 11th place, eight shots back of Wolff. (Reporting by Frank Pingue in Toronto; editing by Ian Chadband and Ken Ferris)