Marsh, McCoy, McCready, Williamson Reach Semis October 8, 2013 | Birmingham, Ala. By Brian DePasquale, USGA

Kenneth McCready eliminated Todd Mitchell in the longest match (20 holes) of the 2013 U.S. Mid-Amateur. (USGA/Steve Gibbons)

Kevin Marsh, 40, of Henderson, Nev., edged Ken Tanigawa, 45, of Phoenix, 2 and 1, to lead the four quarterfinal winners Wednesday morning at the 2013 U.S. Mid-Amateur Championship, held at the par-71, 7,173-yard Country Club of Birmingham’s West Course.

Marsh, the 2005 U.S. Mid-Amateur champion, was a conceded a 14-foot par putt on the 17th hole after his opponent found the right fairway bunker off the tee, leading to a double bogey. Marsh advanced to Wednesday afternoon’s semifinals against Michael McCoy, 50, of West Des Moines, Iowa, who eliminated Bradley Bastion, 28, of Clinton Township, Mich., 7 and 6.

Third seed Bill Williamson, 36, of Cincinnati, and 25-year-old Kenneth McCready, of San Diego, also advanced to the semifinals.

"It’s what I have been doing all week, somehow finding a way to win," said Marsh, who has reached the Mid-Amateur semifinals for the third time. "I am competitive, it doesn’t matter if it is the first round or the final round, I want to win."

Marsh, seeded fourth in the match-play bracket after stroke-play qualifying, took a 2-up lead on No. 15 with a par, but Tanigawa, a recently reinstated amateur who played six years on the Japan PGA Tour in the 1990s, sliced that deficit by hitting his approach shot to within 2½ feet for a birdie on the following hole.

Marsh, who upended defending champion and 2013 USA Walker Cup member Nathan Smith in the second round, hit his tee shot to the left of the cart path on the par-4 17th, but recovered by lifting his second shot over an oak tree to the right fringe of the green. Meanwhile, Tanigawa found the closely-mown area to the left of the green with his third shot and took two more strokes to find the putting surface.

Williamson won five consecutive holes on the outward nine en route to an 8-and-6 victory over Matthew Schneider, 25, of Grand Rapids, Minn. Williamson birdied the sixth and ninth holes in that run. He hit a 9-iron to within 15 feet on the par-4 sixth and sank a downhill 10-foot putt on No. 9. Williamson, an attorney, has made 22 birdies in 79 holes played during this championship.

"I am trying to treat this like any other golf tournament; I know it’s not," said Williamson, who advanced to his first Mid-Amateur semifinal. "Mentally that’s what you have to do. I am hitting greens and I am hitting fairways."

McCoy, also reeled off a string of winning holes on the outward nine in beating Bastion. McCoy, who recorded five birdies in the match, won Nos. 3 through 8.

McCoy, the ninth seed who reached the Mid-Amateur semifinals for the third time, made a double-breaking 20-footer for birdie on No. 4 and struck a 135-yard, 9-iron to within 6 feet at the sixth in building a 4-up advantage.

"It is gratifying to still be competitive," said McCoy, who also played in this year’s U.S. Senior Open and U.S. Amateur. "I’ve put a lot of work in; this is the fruit of a lot of hard work."

McCready, the youngest remaining player in the field, defeated Todd Mitchell, 35, of Bloomington, Ill., in 20 holes, the longest match of this year’s championship.

McCready, who won his third-round match Tuesday afternoon by nearly holing a bunker shot on No. 18, continued his dramatic play. The 2011 University of San Diego graduate’s approach shot at the 20th hole, the par-4 second, clipped a tree and fell short of the green. With his opponent in trouble off the tee, McCready chipped to within 5 feet and sank the match-clinching par putt.

In a seesaw match, McCready gained a 1-up lead on the par-5 15th with a bogey, before Mitchell, the 2008 Mid-Amateur runner-up, squared the match with a 12-foot birdie putt on the next hole. Mitchell had an opportunity to close out the match on No. 18, but came up short on a 9-footer for birdie. McCready, who is playing in his third USGA championship, halved the hole with a 4½-foot par putt.

All four semifinalists are now exempt into the next two U.S. Mid-Amateurs. The 2014 Mid-Amateur is scheduled for Saucon Valley Country Club in Bethlehem, Pa., while the 2015 championship will be contested at the John's Island Club in Vero Beach, Fla.

Brian DePasquale is the USGA’s manager of championship communications. E-mail him at bdepasquale@usga.org.