Romero shot his second straight 7-under 65 on Saturday to take a one-shot lead over Fulton Allem (65) and crowd favorite Joey Sindelar (65) heading into the final round of the Dicks Sporting Goods Open.
Romero, who began the day two shots behind first-round leader Joe Ozaki, had 16 birdies and one double-bogey over the two rounds and was at 14-under 130.
Ozaki (70) was alone in fourth at 11 under. Bruce Vaughan (67), the 2007 runner-up in the inaugural year of this Champions Tour event, was tied for fifth at 10-under 134 with Ronnie Black (68).
Sindelar, seeking his first victory since turning 50 and joining the tour in April, started the day three shots behind Ozaki and fell four back when Ozaki birdied the par-5 fifth hole, his fourth straight birdie after opening with bogey.
Ozaki then lost his momentum when his drive at the par-3 seventh hole landed off the left fringe. He muffed his pitch and was unable to get up and down, falling to 11 under.
After parring No. 7 and hitting his drive at No. 8, Sindelar accepted a Binghamton Mets hat from a longtime pen pal, donned it for the hole, and soon tied for the lead.
When she gave me that hat, I thought, This has to be good stuff, Sindelar said.
At the par-5 eighth hole, Sindelar used a fairway wood on his second shot and made the green to set up a two-putt birdie from 40 feet to get to 9 under.
Then came the shot of the day. Positioned 130 yards from the pin at the par-4 ninth hole, Sindelar used pitching wedge to hit a soaring shot that landed 5 feet past the flag and spun back into the cup for eagle, eliciting a huge ovation from the large gallery.
When Ozakis birdie try stopped an inch short, and Romero mishit a 4-footer for birdie, Sindelar was tied for the lead.
Ozaki made bogey at No. 10 after driving the left rough and hitting his second shot over the green. Romero hit his second shot to 6 feet and made his fourth birdie of the day to drop to 11 under and into a three-way tie for the top spot with Sindelar and Allem.
Black moved into contention with four birdies on the front side. He got to 11 under with a 24-foot birdie putt at the par-4 11th and gained a one-shot lead with another birdie at the par-5 12th hole, recovering nicely after plunking his second shot into a greenside bunker. Moments later, Romero birdied the hole to tie him.
With a massive water hazard lining the left side of the fairway all the way to the green, the 15th is usually the toughest hole on the En-Joie Golf Club course and is ranked the 12th most difficult on the Champions Tour. On this day, it was playing under par when the leaders came through, and they continued the trend.
Ozaki made it back to 11 under with a tap-in birdie. Sindelar then recovered from an errant tee shot that landed behind two oak trees along the right side, hitting his second shot through some branches to 12 feet. After Romero drained a curling 27-foot birdie putt to take sole possession of the lead at 13 under, Sindelar sank his putt to remain one back.
Romero birdied 16 and two-putted for par from 86 feet at the par-3 17th hole, but Sindelar continued to apply pressure. He made a tap-in birdie at 17 after his tee shot stopped less than 2 inches from the hole.
Allem finished the day with a 10-foot birdie putt at No. 17, his seventh birdie on a bogey-free round.
Black, playing in only his second Champions Tour event, closed with consecutive bogeys to fall from the lead.
Andy Bean and Phil Blackmoor eagled the par-5 fifth hole, the first two eagles of the tournament. Gary Koch (67), playing just his fifth tournament of the year because of broadcasting commitments to NBC, was at 9 under. Koch is vying for a spot in the Senior British Open in two weeks and needs a big payday here to qualify.