The Australian world number one and Wimbledon champion withstood a barrage of swinging left-handed serves and powerfully-clubbed groundstrokes from Dick Norman before finally advancing 7-6, 3-6, 6-4 in a shade over two hours.
Hewitt's reward is a place in the quarter-finals of the 800,000 Euro grasscourt event, where he will play France's Sebastien Grosjean, a 6-1, 6-4 winner over Todd Reid.
Hewitt was made to fight for his victory over the 2.03 metre Norman on a slick grasscourt and after nicking the opening set on a tiebreak he was powerless to prevent Norman from charging through the second to square matters at Queen's Club.
With clouds gathering overhead, the two seemed inseparable in the third set as it lurched towards what looked like an inevitable tiebreak.
At 4-4, Norman threw everything at Hewitt, forcing the top seed to fight off six break points.
A cheeky lob over the enormous Norman clinched Hewitt the game and five points later the match was his when the Belgian's backhand rolled along the turf into the net.
In later action, second seed Andre Agassi takes on former Wimbledon champion Richard Krajicek while British number one Tim Henman meets France's Cyril Saulnier.
