The victory at home helped Qatar climb out of the relegation zone in the Qatar Stars League standings, moving three places up from 11th to eighth position.
This marked Tau's first league match since his arrival at the club from Egypt's Al Ahly a few weeks ago. He did not participate in the King's game against Al Sadd, where Qatar achieved a 1-0 victory away from home last week due to illness.
The former Brighton and Hove Albion winger made his official debut for Qatar during their recent heavy loss against Al Nasr in the Qatar-UAE Super Cup.