12:04 PM PT -- A source close to Anyanwu confirms to TMZ Sports ... the hoops star suffered a collapsed lung, burns, cuts and scratches in the accident, but he's expected to fully recover.
"We're thankful right now he's just alive," the source said.
Obinna Anyanwu -- a top H.S. basketball star who has offers from Arizona and USC -- was injured in a serious car crash this weekend ... just hours after his team's championship game.
The tragic scene went down in San Diego ... where the teenager was reportedly driving home from a friend's house shortly after leading his Cathedral Catholic squad to the Open Division boys basketball title Saturday.
Anyanwu was driving on the 163 when a car forced him to crash into a guard rail, according to the San Diego Union-Tribune.
The report says after Obinna got out of the car ... he was hit by another vehicle -- causing major injuries.
The high school junior was rushed to the hospital with a collapsed lung and other ailments. His current condition is unknown.
We've reached out to both Anyanwu's school and his coaches ... but so far, no word back yet.
The 6-foot-7 power forward is a high school hoops superstar who's considered one of the top recruits in the 2021 class. Rivals.com has him ranked as the No. 76 junior in the country.