A three-goal blitz in the opening 11 minutes set the foundation for Pompey who also brought to an end Newcastle’s unbeaten home record while rising to fourth on the standings with 22 points from 12 games.
Portsmouth also recorded their first win at St James Park since 1949.
Not only is Mwaruwari scoring goals regularly to step into the rare comfort of being at the top of the scorers charts, the Zimbabwean is also doing it in some style.
After Noe Pamarot had ushered Pompey into the lead, Mwaruwari then took it upon himself to add his name on the scoring board with an unusual left foot volley before John Utaka added the third in similar execution.
On an afternoon when Newcastle’s Brazilian defender Claudio Capaca was so terrible he had to be substituted after just 18 minutes, Mwaruwari’s finish was laced with the familiar aggression and the odd left foot artistry.
Using his strength Mwaruwari overcame a hesitant Capaca before curling in a sweet volley with his left that affirmed his position as the leading striker in the Premiership.
With eight goals to his name the 29-year-old striker has opened a two-goal cushion at the top of the charts with Emmanuel Adebayor trailing behind on six goals along with teammate Cesc Fabregas and Nicolas Anelka of Bolton Wanderers.
Just a quarter of the season gone, Mwaruwari has already overhauled his six-goal total from last season.