WRAPUP 15-Protests hit Tehran after Ahmadinejad wins poll

* Protests erupt over Ahmadinejad's election victory

* Interior minister says Ahmadinejad gets 63 pct of vote

* Challenger Mousavi denounces result as "dangerous charade"

* Clinton says monitoring election outcome closely

(Adds analysts' quotes)

By Parisa Hafezi and Fredrik Dahl

TEHRAN, June 13 (Reuters) - Thousands of people clashed with police on Saturday after the disputed election victory of President Mahmoud Ahmadinejad sparked the biggest protests in Tehran since the 1979 Islamic revolution.

Supreme Leader Ayatollah Ali Khamenei told Iranians to respect Ahmadinejad's victory in a presidential election that his closest challenger described as a "dangerous charade".

Ahmadinejad's triumph in Friday's vote upset expectations that reformist candidate Mirhossein Mousavi might win the race.