Navajo got a pair of cruicial three point baskets from freshman Sarah Bates down the stretch to send the game in overtime.
Blair unsuccessfully used the delay game in the fourth period and missed seven free throws in the final eight minutes
"We told them (before the overtime) this was our ball game," said Navajo coach Staci Wilson.
And once it got to overtime it was all Navajo.
The Lady Indians never trailed in the four-minute period. Megan Moore scored seven points in overtime and Mandy Medlock added the other three.
Bates scored 21 points to lead Navajo. Moore poured in 16 points while Medlock had 13 points.
Blair was led by Ashton Rackliff's 26 points. Kendra Shaw finished with 11 points.
The victory sent the Lady Indians into Saturday night's finals where they were to have played Sentinel.
NAVAJO 58, BLAIR 51
Blair - Brazell 1-0-2, Kenedy 3-1-9, Shaw 4-3-11, Roberts 1-1-3, Rackliff 11-3-26. Totals 20-8-51. 3 point goals - Kenedy 2.
Navajo - Medlock 5-3-13, Moore 5-5-16, Godfrey 3-0-6, Bates 6-7-21, Childs 1-0-2. Totals 20-14-58. 3 point field goals - Medlock, Moore, Bates 2.
Blair 16 7 16 9 3 - 51
Navajo 10 10 14 14 10 - 58