Out of the top 10 seeds in each event — 20 players total — only one lost in Monday’s round-of-32 matches. That one came on the boys side, where 25th-seeded Bo Wardynski of Parker defeated eighth seed Freddie Gluck of Boulder, 1 up. Wardynski won the 18th hole with a bogey to advance.

Jack Castiglia of Lakewood and Amy Chitkoksoong of Aurora, the respective No. 1 seeds, led the way in advancing to the Sweet 16 in the Junior Golf Alliance of Colorado major. Castiglia beat 32nd-seeded Davis Long of Lafayette, 6 and 5. And Chitkoksoong, the 2017 5A state high school champion, moved on thanks to a bye.

Among the boys into the round of 16 were 2016 state high school tournament winners Kyle Pearson of Highlands Ranch and Luke Trujillo of Colorado Springs. Pearson, seeded second, finished second in the CGA Match Play in June.

On the girls side, among the winners Monday were Natasha Brandy McClain of Denver (the No. 2 seed), Sydney Eye of Golden (3), Josie Baker of Sherman Oaks, Calif. (4) and Meghan Vogt of Broomfield (5).

Two rounds of matches — the round of 16 and the quarterfinals — will be held Tuesday for both boys and girls. Then the semifinals and finals are scheduled for Wednesday.

For the brackets for each tournament, click on the following: BOYS, GIRLS.