PHOENIX (AP) -- UCLA can make a double-digit victory look difficult.
Top-seeded UCLA (34-3) will play No. 3 seed Xavier on Saturday for a trip to its third consecutive Final Four.
The Bruins were more relieved than happy to survive the Hilltoppers, who took advantage of UCLA's sloppy play to pull within four points late in the game.
"Unacceptable, unacceptable, unacceptable," Love said. "That's all I can say.
"It was unacceptable the way we played in the second half. If we're going to keep playing like that, we're not going to be in this tournament very long."
The Bruins routed overmatched Mississippi Valley State in the first round but haven't resembled a No. 1 seed since. They sweated out a two-point victory over Texas A&M in the second round.
"That was another exciting game for all the Bruin fans out there," UCLA coach Ben Howland said. "We want to keep you guys awake and on the edge of your seat."
Without Love, the Bruins would be in hibernation already. Love had 14 rebounds and hit 10-of-14 shots from the floor.
Keefe, a sophomore who has battled back from shoulder surgery last August, played sparingly most of the season.
"I mean, this is why I came back, you know?" Keefe said.
"We just dug ourselves too big of a hole in the first half," Western Kentucky coach Darrin Horn said. "I'm unbelievably proud of my team."
Early on, the Bruins looked primed for a blowout, blitzing the Hilltoppers with a 23-4 run midway through the first half.
UCLA led 41-20 at halftime, but Western Kentucky wouldn't go away. The Hilltoppers began pressing, and the Bruins started to unravel. They had 12 turnovers in the first 15 minutes of the second half and finished with 19, a season high.
The Bruins appeared in trouble when point guard Darren Collison fouled out for the first time this year with 5:39 to play. Collison had four points and four turnovers.
"They came out in some different angles," Collison said. "We didn't read the plays right. Everybody was sped up."
As the U.S. Airways Center crowd got behind them, the Hilltoppers went on a 19-6 run to whittle the lead to 61-57 with 6:50 to play. Brazelton capped the run by scoring eight unanswered points in less than a minute, on back-to-back 3-pointers and a layup.
But A.J. Slaughter missed a 3-pointer that would have pulled Western Kentucky within one point, and then Love scored from close range. Josh Shipp, an erratic long-range shooter, hit a 3 to push UCLA's lead to 68-59 with 4:30 to play.
"That in a nutshell was the game," Horn said. "It changed all the momentum. We had spent so much energy to get back into it, played so hard to get back, if that three goes down and we cut it to one, it's a totally different situation down the finish."
Howland was so desperate to stem the tide that he called his final timeout. Steadied, the Bruins did not let the Hilltoppers draw closer than six the rest of the way.
Perhaps it was no surprise that UCLA let the scrappy Hilltoppers back in the game. The Bruins rolled into the desert on a 12-game winning streak, but they hadn't been dominant. Five of their last eight wins had been by three points or less, and another came after they forced overtime.
The Hilltoppers had won eight straight games and reached the round of 16 for the first time since 1993, when Horn was a sophomore guard. At No. 12, Western Kentucky was the lowest remaining seed in the tourney, along with Villanova.
Early on, Western Kentucky looked the part of a 12th seed. The Hilltoppers came out jittery, with four turnovers in the first three minutes. And they had more turnovers (nine) than field goals (six) in the first half.
Lee made two of his first 13 shots from the floor.
Things were no better at the other end, where Western Kentucky had no answer for Love.
UCLA has had trouble generating offense recently -- Love and Collison scored 40 of UCLA's 51 points in the second-round victory over Texas A&M -- but that all changed during the 23-4 run midway through the first half.
Four players scored during the burst, including Shipp, who hit a 3-pointer to snap an 0-for-11 slump from beyond the arc over the last three-plus games. Western Kentucky called timeout, and several Bruins greeted a relieved Shipp on his way back to the bench.