JOIN USBarnes, Glover in joint lead
PGA Tour rookie Barnes, the surprise pacesetter after the second and third rounds at Bethpage Black, bogeyed the par-four first after driving into the left rough to join playing partner Glover at seven-under, five ahead of the chasing pack.
The duo then teed off at the second, Barnes again ending up in the left rough while Glover found the fairway, before the siren sounded to end play for the day in fading light.
Although they had the option to complete the hole, the co-leaders decided to leave the course and will return for the resumption of the final round at 0900 local time (1300 GMT) on Monday.
Former world number one David Duval, making a popular return to form after spending most of the last eight years in the golfing wilderness, was among their closest challengers, bogeying the first to lie two-under overall after two holes.
Level with Duval in a four-way tie for second were fellow Americans Hunter Mahan and three-times major winner Phil Mickelson, plus Britain's Ross Fisher. Mahan and Bethpage crowd favourite Mickelson, playing his first major since his wife Amy was diagnosed with breast cancer last month, had 16 holes remaining while Fisher was yet to complete the second.
"I feel like if I can get a hot round going, I can make up the difference," left-hander Mickelson said of his bid for a first US Open title.
Triple champion and holder Tiger Woods, who won the 2002 Open at Bethpage, was seven shots off the pace, having knocked in a six-foot birdie putt at the par-four seventh shortly before play was suspended for the day.
For much of a marathon day at Bethpage, the long-hitting Barnes was in firm control in pursuit of his first PGA Tour title, forging six shots clear midway through the third round.
He became only the fourth player to reach double digits under-par at a US Open when he rolled in a 25-foot eagle putt at the fourth, but he began to wobble in the late afternoon.
"If you don't have a little bit of nerves when you're in the heat of competition, and especially in the last group, you're not human," the 2002 US amateur champion said.
Glover, a more experienced campaigner than Barnes, liked his own position atop the Open leaderboard but felt a five-shot cushion could be easily overhauled at Bethpage.
"There are too many great players and the golf course is too good," said the 29-year-old, who clinched his maiden victory on the US circuit at the 2005 Disney Classic.