Bettencourt also carded a 69 on Friday at Brookside Country Club. He held the lead until a double bogey at his final hole dropped him one behind Johnson.
Michael Harris (70), Chris Carnahan (70), Brennan Webb (69), Tom Johnson (69), Scott Taylor (70), Joe Acosta, Jr. (65), Gordy Scutt (67) and season-opening Barton Creek Austin Canadian Tour Pro Am Classic champion Scott Gibson (68) are knotted in third place at minus-5.
Heavy winds on Thursday allowed only 17 players to break par, but the breezes died down on Friday and the scores reflected it. In the second round, 79 players broke par.
Johnson started on the back nine Friday and birdied his first hole. He added another birdie at the par-5 18th, his second in as many days, and collected his second birdie in a row at No. 1.
Johnson's only mistake of the second round came at the second when he yanked his approach. He missed a 7-foot par save, but birdied the par-5 fourth for the second consecutive round to take the lead at 7 under par.
'To be honest, that was quite a boring round for me,' admitted Johnson, who has three tour wins. 'I didn't do anything spectacular, but I didn't hurt myself either. It was just one of those rounds. I didn't get on a roll like I did Thursday. I just couldn't get the putts to drop.'
Bettencourt mixed six birdies and one bogey in his second round and was atop the leaderboard at 9 under par. At the 18th, he dumped his second in a lake, and left with a double bogey.
It was an all-around strange round for Bettencourt. He holed three putts over 35 feet in length, but missed five inside 4 feet.
'Even my girlfriend said 'You made all the long ones and missed all the easy putts' on our drive home,' said Bettencourt, who also has status on the Nationwide Tour.
It was an eventful ride home for Bettencourt, who witnessed a car accident and had to spend an hour with police officers.
Johnson's first-round co-leaders did not fare as well on Friday. Brian Nosler only managed an even-par 72 and is tied for 11th at 4-under-par 140. Daniel Riskam struggled to a 4-over 76 and is part of a group tied for 35th at even-par 144.
The 36-hole cut fell at 2-over-par 146 and 76 players made it to the weekend.