Laird, who started the day three shots behind overnight leader Corey Conners after an opening 70, continued to produce some impressive golf on the demanding Ocean Course at the South Carolina venue.
The 38-year-old, who had finished bogey-bogey on the opening day, wasted no time repairing that damage with a birdie-birdie start after setting out on the back nine for his second circuit.
He rolled in a putt close to 15 feet at the par-4 10th before making a 4 at the 11th with a two-putt from around 30 feet.
After a lovely approach to just over 14 feet, Laird had a chance to join clubhouse leader Phil Mickelson on five-under only to run his downwind birdie attempt three-feet past then miss the return.
The four-time PGA Tour winner, who recorded his best finish in this event when tying for 42nd behind Rory McIlroy in 2012, was back to level par for the day after a bogey at the 15th.
Laird then covered the remainder of the closing stretch on his front nine without giving himself any real stress before sending his tee shot at the par-3 fifth into a waste area and not getting up and down.
He also dropped a shot at the eighth, another short hole, before closing with a solid par-4 for a 73 to sit on one-under, just four shots off the lead, shared by Phil Mickelson and Louis Oosthuizen.
Playing the course the other way around, MacIntyre suffered an early setback with an opening bogey after finding the left rough and being unable to make the green from there.
The 24-year-old has developed a useful knack, though, of carding birdies straight after setbacks and did so once again on this occasion - and not just once.
He followed a disappointing 6 at the seventh with back-to-back gains, rolling in a 32-footer at the eighth then converting another birdie putt from close to 16 feet at the next.
After being in two waste bunkers, the 2019 European Tour Rookie of the Year started for home with a bogey and, though following that with a two-putt birdie from close to 60 feet at the 11th, he then had back-to-back bogeys at the 15th and 16th.
That left him facing two of the toughest holes on the course with little room for error, but it was job done for MacIntyre in terms of making the cut in all five majors he has teed up in as the left-hander closed with solid pars at both the 17th and 18th.
In doings so, he signed for a 73, giving him a four-over total as he succeeded where world No 1 Dustin Johnson and second-ranked Justin Thomas both failed by progressing to the weekend.
Mickelson, the 2005 winner, came home in 31 as he set the clubhouse target, with 2010 Open champion Oosthuizen on course to beat that until he finished with a bogey.
Two-time winner Brooks Koepka is lurking ominously on four-under, one ahead of and Masters champion Hideki Matsuyama, as well as South African duo Branden Grace and Christiaan Bezuidenhout.