Known until this month as Stephen Cherono, Shaheen won the world steeplechase title for Qatar after switching nationalities to secure his economic future.
Determined to beat a Kenyan trio including his older brother Abraham and defending champion Reuben Kosgei, Shaheen set off at a startling pace accompanied by team mate Khamis Abdullah Saifeldin.
Kenyan Ezekiel Kemboi gave chase and caught up with Shaheen but the pace inexplicably slowed at 2,000 metres, allowing the chasing pack to move into contention.
Over the last 800 metres, Shaheen and Kemboi accelerated again and the race was decided on a sprint finish in which Qatar's new acquisition proved the stronger.
"I don't understand Arabic but my whole heart was trying for Qatar," Shaheen said.
Kemboi added: "It was too hot, it was tough and that's why I got second."
Maria Mutola, supreme over the women's 800 metres for the past decade, looked briefly vulnerable in the finishing straight after her training partner Kelly Holmes kicked on the final bend.
She fought back to draw level with the Briton then pulled away to win in one minute 59.89 seconds.
"In the end it was a slow tactical race so I just went to the front to control it from there and rely on my speed in the last 100 metres," said Mutola. "I just gave it all I had."
YOUNG FULFILS POTENTIAL
Austrian Stephanie Graf, who finished second behind her Mozambican rival in both the last Olympic Games and world championships, withdrew from the race on Tuesday morning after a cut in her foot required stitches.
Jerome Young, once the heir apparent to Michael Johnson in the 400 metres before injury disrupted his career, finally fulfilled his potential with victory over world indoor record holder Tyree Washington.
"Today was a big moment for me," said Young, before paying tribute to former Olympic and world champion Johnson.
"It was a learning experience, he was the teacher and I think I learned very well from him being in the race in all the years I was running against him."
German discus thrower Lars Riedel, seeking to match pole vaulter Sergei Bubka by winning a sixth individual gold in the same event, finished fourth in Tuesday's final.
Lithuania's Olympic champion Virgilijus Alekna bettered his previous best with a first throw of 69.69 metres to win the title.
Russian Tatyana Lebedeva retained her women's triple jump crown with a leap of 15.18 metres to beat Cameroon's Francois Mbango Etone, who took silver for the second time in a row.
American sprinter Jon Drummond, who stopped competition for nearly an hour on Sunday when he was disqualified from the 100 metres second round heats, withdrew from the championships on Tuesday.
"My spirit is broken because it has always been my desire to provide entertainment for the fans," Drummond said."
"During Sunday's 100 metres quarter-finals I felt very strongly that I was disqualified from the race unfairly and I protested my disqualification."
The United States 4x100 relay team will now start without Drummond, Olympic 100 champion Maurice Greene, who was injured in the semi-finals, and world record holder Tim Montgomery who has decided to return home.
