The Hawks' 19.6 (120) to 7.14 (56) victory at Adelaide Oval on Saturday night gives their new coach Sam Mitchell consecutive wins to start his tenure.
And it puts Port Adelaide, rated by most pundits as a flag fancy, in early-season strife with successive defeats.
Lewis finished with five goals and veteran forwards Jack Gunston and Luke Breust booted three each for the sharp-shooting Hawks, who slotted 13 goals without a miss from set shots.
A pair of Hawks scored two goals: Dylan Moore, who was involved in nine of his side's scores, and Chad Wingard, who was substituted at halftime because of a hamstring injury.
Hawthorn's Brownlow medallist Tom Mitchell (28 disposals), James Worpel (six inside 50s) and Jack Scrimshaw (22 touches) were other standouts.
And the Hawk defence, marshalled by James Sicily (seven marks, 20 disposals) and Jack Frost, was downright miserly on a bleak night for the Power.
Port utility Sam Powell-Pepper scored three goals - all in the third term - and the home side had the top four ball-winners on the ground in Travis Boak (39 disposals), Karl Amon (39), Ollie Wines (36) and Zak Butters (29).
But the Hawks were never headed after keeping the Power goal-less in the first term to craft a 3.2 to 0.3 lead at quarter-time.
Hawthorn extended their advantage to 28 points at halftime after rallying when Port snuck within nine points - the closest the home side could get thereafter.
The second quarter was book-ended by remarkable snapped goals from Gunston.
The veteran Hawk slotted one early with a curling right-footer near a boundary line, and threaded another late with a left-footer from an acute angle near the opposite boundary.
Hawthorn's 8.4 to 3.6 halftime advantage belied key statistics.
Port had a 73 more disposals, three more entries into their attacking 50 metre zone, more tackles, marks and clearances - and the top five disposal-getters in the half.
But the Power's concerns turned into outright alarm in a third term dominated by Hawthorn spearhead Lewis - the 38-gamer booted four goals in a 28-minute purple patch.
The Hawks scored six goals in the quarter and were 44 points up before two late strikes from Port's Powell-Pepper reduced their lead to 36 points at the last change.
Hawthorn then kept their hosts goal-less again in the final quarter while kicking another five, with Port's woes compounded by fullback Tren McKenzie being subbed out with a suspected ankle injury.
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