The Rockies' No. 8 prospect matched a career high with 11 strikeouts, including eight in a row in the middle innings, but one mistake sent his Modesto Nuts to a 2-1 defeat to the Stockton Ports.
Bettis (5-6) worked seven innings and gave up both runs -- one earned -- on three hits. The longest was Michael Choice's first-inning solo shot. Choice, the A's No. 3 prospect, has gone yard in six of his past seven games to raise his total to a California League-leading 23.
An errant release point resulted in the fat four-seam heater that Choice crushed.
"If I could get that pitch back ... " said Bettis, who walked two. "He hit the crap out of it.
"I definitely could have been better than I was in the first couple of innings. They were sitting on my fastball and when I went back to the dugout, I was thinking, 'I need another pitch when I go back out there.'"
Naturally, that pitch was his changeup. The 22-year-old right-hander paired it with his fastball and sat down eight straight on strikes and 11 in a row overall before leadoff man Myrio Richard's single in the sixth. He fanned every Port at least once, except Richard.
"I really didn't know I was a on a run like that until the [fifth] inning, when I struck out a couple more guys," Bettis said. "I was like, 'Are they just missing my pitches or what's going on?'"
His crooked number in the category wasn't altogether surprising. The 2010 second-round Draft pick out of Texas Tech set his personal best on May 3 when he struck out 11 in a six-inning outing against High Desert.
Bettis ranks second in the Cal League with 114 strikeouts over 105 2/3 innings. Visalia's Tyler Skaggs has piled up 125 over 100 2/3 frames.
The Lubbock, Texas, native hasn't relied strictly on the strikeout. Since surrendering nine runs on 11 hits over five innings on May 30, he's 3-2 with a 1.48 ERA in six starts.
"Since that one outing that was really embarrassing in Inland Empire, I took it the right way," he said. "I made sure no one was going to outwork me again."
Bettis did not completely revamp his routine between starts, he simply gave each act -- running, lifting, playing catch, throwing side sessions -- more attention.
"Working out smarter," he said. "You have a lot more confidence in all your pitches. I definitely have been feeling a lot better."
The Nuts scored a run on four hits against Ports starter Daniel Straily (8-5), who fanned eight over eight innings. Kent Matthes took his lone mistake over the left-field fence leading off the fifth to get Modesto within 2-1.