Ethiopian-born Desalegn, 24, won in a time of 8min 44.59 sec, almost three seconds ahead of Bahrain’s Ruth Jebet, who finished second.
Despite her success, however, Desalegn revealed afterwards that she was not fully fit.
“I needed to push hard, to meet qualification standards for Portland (World Indoor Championships),” she said.
“I had suffered many setbacks over the last three years due to a problem with my Achilles. I’m still not one hundred per cent fit, but I’ll fight for a medal at the Worlds.”
The World Indoor Championships take place next month in the United States.
Meanwhile, there was further home country success for Qatari athletes with gold medals in the men’s 400 and 1,500m. Abdelalelah Haroun set a championship record of 45.88 secs to top the podium in the 400m.
“I gave all I had left in the tank, but I certainly can go faster,” said the teenage star.
“My target here was to win the race, nothing more. For me, the next stop is Portland.”
Last week, the 19-year-old became the first man to run 500m in less than a minute, clocking a time of 59.83secs at a meeting in Stockholm.
Another home winner Sunday was Mohamad Al-Garni, who regained his title at 1,500m.
Their success follows gold for Qatari high jumper Mutaz Etta Barshim on Friday.
Elsewhere, long jumper Mayookha Johny secured India’s first gold medal at the event in the women’s long jump with a leap of 6.35m.
