"Game-changing at-bat, in my mind," said Padres interim manager Pat Murphy.
Kemp fell behind in the count, 0-2, then fouled off two pitches and then laid off two very close pitches before doubling over the head of Rockies' center fielder Charlie Blackmon on the seventh pitch of the at-bat.
Kemp had been 1-for-13 in his career against Betancourt.
"For sure," Kemp said when asked if that was hit best at-bat of the night. "I don't think I've had too much success against Betancourt and I've faced him a lot.
"I'm just trying to get that hit and drive in that run. I got a good pitch to hit and stayed in the center of the field."
Kemp, who had hits off three different pitchers on Friday, actually got all four of his hits going up the middle, including his home run and then, finally, the triple that gave him his first cycle -- and the same for the Padres.
Kemp's four-hit game raised his average to .262 going into Saturday's game -- the highest it's been since May 19 (.266).
"I feel good. I'm trying to have more consistent at-bats, have better at-bats and not waste at-bats," Kemp said.
"That's a good sign when I'm hitting the ball right up the middle. It's just getting good pitches and taking good swings."
He has certainly gotten hits in bunches since the All-Star break. Heading into the game Saturday, he's hitting .305/.370/.537 with five home runs and 20 RBIs in 95 at-bats since the break.
He has a wRC+ (weighted runs created) of 153 in the second half with five home runs and 20 RBIs.
"I can't remember the time it happened, I think it was sometime in Pittsburgh. I just thought, 'This guy is as good as there is out there.' He's put together some great at-bats," Murphy said. "He's been awfully good. I'm not shocked by it.