Two-time reigning boys lacrosse champion Mt. Lebanon will start its latest title defense as the No. 1 seed in the WPIAL playoffs.

The Blue Devils (12-4) drew the top spot in WPIAL Class 3A, and South Fayette (17-0) was seeded first in 2A in brackets released Thursday.

The playoffs start with first-round games Tuesday and Wednesday. The finals are May 21-22 at Upper St. Clair.

Seeded behind Mt. Lebanon in Class 3A were No. 2 Shady Side Academy (10-7), No. 3 Upper St. Clair (10-6) and No. 4 North Allegheny (9-8).

Mt. Lebanon defeated North Allegheny, 15-10, in the finals last season. The title was the Blue Devils’ sixth overall.

South Fayette is seeking its first WPIAL title but faces a familiar foe. Second-seeded Mars (15-2) has won the past eight WPIAL Class 2A titles. Mars defeated South Fayette, 16-5, in last year’s final.

Hampton (14-3) was seeded third in 2A, and Peters Township (10-6) was fourth.

Class 3A

First round

All games Wednesday, times TBA

8-Central Catholic at 1-Mt. Lebanon

5-Pine-Richland at 4-North Allegheny

7-Canon-McMillan at 2-Shady Side Academy

6-Fox Chapel at 3-Upper St. Clair

Class 2A

First round

All games Tuesday

1-South Fayette – bye

9-Indiana at 8-Franklin Regional, 7 p.m.

4-Peters Township – bye

12-Chartiers Valley at 5-Sewickley Academy, 6 p.m.

2-Mars – bye

10-Quaker Valley at 7-Bethel Park, 7 p.m.

3-Hampton – bye

11-Shaler at 6-Penn-Trafford, 7:30 p.m.