Oakland's Martha Fabela won her third straight match Monday to advance to the semifinals of the Youth World Boxing Championships in Sofia, Bulgaria.

Fabela, 18, who trains at King's Gym in Oakland, defeated Turkey's Sema Caliskan 2-0 in the quarterfinals of the middleweight (152 to 165 pounds) division. She will face Davina Michel of France in Wednesday's semifinals.

The event is a qualifier for the 2014 Youth Olympic Games, Aug. 16-28 in Nanjing, China. The U.S. can send three boxers from all weight classes among boys and girls to the event, so the top three American finishers will earn bids.

Fabela opened the tournament with a 3-0 decision over Diem Quynh Luu of Vietnam on Thursday, then beat Celina Agwu of Nigeria 3-0 on Friday.

The middleweight championship bout will be held Thursday.

Fabela, who began boxing at the age of nine, is competing in just her second international tournament. She won the Youth Continental Championships in Quito, Ecuador in March, prevailing in her only bout.

Earlier, she qualified for this event by winning the Junior Youth Nationals at Reno in January.