Knowles first raced with the sun at his back and a light tail wind awaiting him over the final 10-15 meters of the 110 hurdles, in which he topped his personal-best of 14.67.
As for the 300, Knowles led midway, but faded over the final 100 meters.
Speaking of shattering personal bests, Monroy did just that in finishing 13th in the seeded 3,200 in a mark of 9 minutes 14.20 seconds, well ahead of his previous top mark of 9:18.
"I haven't ran in a competitive race in a while, so this was great," Monroy said. "I really wasn't sure how I'd do, but I did pretty good."
Davis began by finishing fourth in the seeded 100-meter dash in 10.79, but felt he could have done better if he hadn't been thrown off by a false start by El Camino's Dylan McCloskey.
"The false start bothered me because I was ready to go," Davis said. "I could have done better, but I have a couple of weeks before [the Mt. SAC Invitational] to get better."
Davis later earned seventh place in the invitational 200, speeding to a mark of 21.98.
Glendale senior Sophia Amodia picked up the area's lone victory at the two-day long meet, by winning her open 300 hurdles heat in 45.24.
Amodia entered with a personal-best mark of 46 seconds and held off a stiff challenge from Ayala freshman Jaela Williams (45.45), who momentarily took a lead at 250 meters.
"She was gaining on me and I had to give everything I had," Amodia said. "I was disappointed with my results in the 100 hurdles [47th in 16.66] and wanted to make it up."
Amodia's time was 10th-best overall, behind overall leader Fleming Tayler (43.52) of M.L. King.
Flintridge Prep's Kate Kennedy also raced in the open 300 hurdles and finished seventh in her heat and 21st overall (46.34).
Flintridge Sacred Heart Academy began local competition in the 400 open relay.