For Costa Mesa resident Reese Stalder, the 112th annual Southern California Junior Sectional Tennis Championships offer a chance to build on a very solid high school season.

For Newport Beach resident Austin Di Giulio, the tournament could be another big title after he won in Ojai in April.

As of Friday night, seedings had not been released. Stalder and Di Giulio still figure to be among the favorites in the boys' 18 and 14 singles divisions, respectively, at the Junior Sectionals, which begin Saturday. Overall, there are 31 Newport-Mesa residents competing in the tournament, the largest junior tennis tournament in the country.

Stalder is ranked No. 9 in the SoCal 18s, and Di Giulio is No. 12 in the 14s. They won't be in singles action until next week, as they have qualified for the main draw. Qualifying for that main draw starts Saturday, though, for the boys' and girls' 12-18 divisions. Boys' and girls' 18 doubles play, as well as the main draw of the boys' and girls' 10s, also start Saturday.

Stalder and partner Billy Rowe of Coronado are the No. 2 seeds in boys' 18 doubles and have a first-round bye, starting their tournament in the round of 32 on Sunday. Saturday, however, will be quite a busy day for a number of other doubles players.

Corona del Mar High's Bjorn Hoffmann, who has qualified for the main draw in boys' 16 singles, will be in doubles action Saturday with his partner, Derek Chen of San Gabriel. Hoffmann and Chen play Lyndon Bui of Orange and Danny Nguyen of Long Beach in the round of 64 at 1 p.m. at Costa Mesa Tennis Center. Hoffmann, ranked No. 3 in Southern California in the 16s, could also go far in singles. Last year, he advanced to the 16s quarterfinals as an unseeded player.

CdM's Chaz Downing, partnered with Max Cancilla of Marina High, also will be in doubles action. Downing and Cancilla will face Ryan Brown and Evan Han of Manhattan Beach in a round of 64 match at 8:30 a.m. at Fountain Valley Tennis Center.

Girls' doubles play begins Sunday. The all-local team of Riley Gerdau and Siena Sharf of CdM will play Jay Kim and Joy Kim, both of Los Angeles, in a round of 64 match at 9:30 a.m. at Los Caballeros in Fountain Valley. Newport Beach's Danielle Willson and partner Jadie Acidera of Anaheim play Alexandra Kuo of La Jolla and Katherine Nguyen of Fountain Valley in a round of 64 match, Sunday at noon at Los Cab.

The other local in the girls' 18 doubles draw is Newport Beach's Mackenzie Worsnop, teamed with Sara Khattab of Rancho Palos Verdes. Worsnop and Khattab play Estelle Wong of La Jolla and Hannah Zhao of San Diego in a round of 64 match at 11 a.m. Sunday at Los Cab.

Locals competing in the boys' 10s main draw Sunday include Adam Bain of Newport Coast, Perry Di Giulio — Austin's younger brother — of Newport Beach and Matthew Holiday of Costa Mesa. All will be in round of 64 matches on Sunday.

Newport-Mesa juniors who have qualified for the main draw in their respective divisions also include CdM's Ryan Andrews (boys' 18s), Max McKennon of Newport Beach (boys' 12s), Kristina Evloeva of Newport Coast (girls' 14s) and Skyler Grishuk of Newport Beach (girls' 12s).

Max Pham of Newport Coast (boys' 18s) will have to play through qualifying. But Pham, who will be a junior at Fairmont Prep in Anaheim, went the furthest of all local juniors last year, making it to the boys' 16 semifinals.

Other Newport-Mesa boys in singles qualifying this weekend include Matthew Holiday (10s), Jacob Holiday (16s), Alastair Hurry (18s), Alexander Reyna (16s), Daniel Day (12s), JP Day (12s), Thomas Day (14s), Ari Coskinas of CdM (16s), Adam Langevin of Sage Hill (16s), Noah Lawson (18s), Gavin Leonard of Newport Harbor (16s), Grant McCabe (14s), Erin O'Connor (16s) and Kyle Pham (14s).

On the girls' side, other local players in qualifying include Claire Nguyen (12s), Karina Grover (12s), Willson (16s) and Worsnop (16s).

The tournament continues through June 29, with championship matches at Los Cab. No Newport-Mesa player has won a title at the tournament since Joseph Di Giulio won the boys' 14s title in 2009.