Skylar Diggins scored nine points and dished out 11 assists but it wasn't enough as Tulsa fell to Washington 95-90 in Diggins' home debut.
The 11 assists are the most ever by a Notre Dame alum in a WNBA game and the most by a rookie in a WNBA game in five years.
Trailing by two with 23.3 seconds left in regulation, Glory Johnson hit two free throws to tie it at 88. In overtime the Mystics outscored Tulsa 7-2. Ivory Latta's two free throws with 16.2 seconds left in OT sealed the win. Latta scored 27.
Matee Ajavon added 19 points, Crystal Langhorne 16 and Kia Vaughn 10 for the Mystics (1-0).
Johnson had 20 points and 14 rebounds to lead Tulsa while Liz Cambage added 21 points and 10 boards.
The Shock (0-2) was led by Roneeka Hodges' 22 points. Hodges was 8-of-11 from the field. Her six 3-pointers tied her career high.
Diggins and Tulsa will play in Chicago on Sunday.