Hirata played bogey-free at Port Royal for a 64 to join Blanchet at 13-under 129 on Friday. Hirata had never shared the lead after any round in his rookie season on the PGA Tour.
Cameron Davis was the only Australian to make the cut, following up his opening one-under 70 with a sparkling seven-under 64 in the second round.
His bogey-free round was littered with seven birdies and left him at eight under in a share of 23rd place.
Fellow Aussie Aaron Baddeley missed the cut after rounds of 69 and 75 left him at two over.
Blanchet tugged his drive on the par-4 closing hole and was hoping it would land in the bunker to at least give him a reasonable lie. It cleared the sand, but his ball was on a slight slope above his feet, leaving him a blind shot to a front pin.
The wedge came out perfectly, setting five feet away for a final birdie.
"Had a pretty uphill, above-the-feet lie and completely blind shot," Blanchet said.
"It was kind of a fun creative one, which I think you've got to be pretty solid at this week with the wind. Can't just take your stock shots, so it was a good way to end it."
Seamus Power, who won the Bermuda Championship in 2022 when the Irishman was among the top 50 in the world, shook off a poor finish to the opening round with a bogey-free 64. He was one shot behind, along with Corey Conners (67), Eric Cole (65), Ben Silverman (67) and Danny Walker, who birdied his last two holes for a 67.
Wind is the strongest defence of Port Royal, and it has not been up to full strength through two rounds. That much was evident by the scoring, so low that the 36-hole cut came at five-under 137.
Among those missing the cut were defending champion Adam Schenk and Chandler Phillips, who came into the tournament at No.98 in the FedEx Cup Fall standings. Five tournaments remain for players to finish in the top 100 and keep full status for 2027.
