Boetsch, who won four consecutive fights in 2011 and 2012, falls to 1-3 in his last four appearances.
Jim Miller might be finding his groove again.
Miller (24-4) earned the 14th submission win of career with a first-round finish over fellow lightweight Yancy Medeiros.
After hurting Medeiros (9-2) with a straight left, Miller jumped on a guillotine choke during a scramble and eventually put Medeiros to sleep. Referee Mario Yamasaki called an end at the 3:18 mark, after Medeiros slipped into unconsciousness.
"Once I got my right leg out, I had a good angle," Miller said. "I felt it cutting off circulation and I knew he'd tap or go out.
"Im here to beat the best, it's not about the belt for me."
" I've got the record for most submissions in my weight class and I'm looking to add to that record every time."
Medeiros attempted to use his height and reach advantage to keep Miller on the end of his punches, but failed to land anything significant. When Miller caught him on the chin with the left, he smiled and waved him forward -- still unsteady on his feet.
Miller jumped at the invitation and moved in on Medeiros with a flurry. After a brief tie up, Medeiros dropped on a takedown, which opened a window for the guillotine. Medeiros fought the choke valiantly, even electing to go out rather than tap.
It's the second consecutive first-round finish for Miller. The New Jersey native subbed Fabricio Camoes via armbar at UFC 168 in December.
Medeiros, who saw a win over Yves Edwards in November change to a no-contest after he tested positive for marijuana metabolites, falls to 0-2 in the UFC.
The final sequence started when Holloway (9-3) hurt Fili in an exchange along the fence. As Fili dove for a takedown, Holloway rolled into a guillotine choke that produced the tap at 3:39 of the round.
"I was sick all week. I really only got out of bed for my weight cut and my media obligations," Holloway said. "It was incredibly tough, but I've got a family to feed and I don't make any excuses.
"My strength and conditioning for this camp was awesome and that allowed me to power through the sickness that I had."
Fili (13-2) jumped ahead of Holloway on the scorecards early, as he dictated range on the feet and worked behind a steady game plan of leg kicks.
The fight changed quickly in the next round, when Holloway hurt Fili with a spinning back kick to the midsection. Fili didn't go down from the shot, but it appeared to sap some of the bounce in his step.
A member of Team Alpha Male in Sacramento, Fili picked up his takedown attempts in the second half of the fight. He had limited success getting Holloway down however, converting just three of his 12 total attempts.
In addition to the spinning back kick, the straight right hand was a major weapon for Holloway. The volume of his strikes appeared to weigh on Fili, as he was clearly the more tired of the two in the final round.
Holloway, 23, improves to 5-3 in the UFC. He recorded a second-round TKO over Will Chope at a UFC Fight Night event in January.
Fili falls to 1-1.