The Woods cruised to a comfortable victory in this FA Trophy fixture and should have won by a much-more convincing scoreline.
Manager Colin Payne was forced into ringing the changes with Lee Holland and Otis Williams starting their first games for the club while Mark Burgess, newly recruited from Boreham Wood, made his debut in place of the injured Bradley Hewitt. Rob Ursell was ruled out with a back injury while Ryan Tackley was unavailable.
The visitors were on a great run of form which included an FA Cup replay victory over Conference South side Welling United last Wednesday evening, but they were missing their regular strike pairing of Denva McKenzie and Paul Scott.
The Woods took command from an early stage with Otis Williams going close in the first minute and then should have taken the lead in the ninth minute.
Sean Sonner flicked a header on to Michael Gordon who burst into the box and squared to Abdul Yoki but the winger saw his effort saved by goalkeeper Robert Tolfrey who spread himself well to block at close range.
Three minutes later, Whyteleafe responded with Robert Smith running on to a long ball from Ali Reeve and firing a snapshot into the near post which Mitch Swain blocked well. From the resulting corner, Nicky Greene swept a shot well over and Northwood then took control once again.
The opening goal came after 21 minutes as a defensive error allowed Yoki to run towards goal. He rode two challenges and the ball ran loose towards Otis Williams who coolly finished with a crisp strike which gave Tolfrey no chance.
Just a minute later, good work by Sonner saw him cross to John Christian who looked sure to sweep the ball home but somehow steered his shot wide of the post. Two minutes later a ball from Burgess put Sonner through one-on-one with Tolfrey but the 'keeper again did well to block at his feet.
The Woods had become profligate and Leafe almost made them pay on the half-hour. Firstly, a long-throw by Richard Harris was met by the head of Greene but straight at the 'keeper and then Greene chargeddown a Holland clearance and set up Ronnie Green for a shot but Swain was equal to it again.
It was only a brief respite for the visitors as the Woods stormed forward again with Otis Williams turning creator, getting past his marker and setting up Sonner who sliced his shot wide of the target. After 34 minutes a Danny Murphy free kick found Sonner again and his quick turn and shot flashed only just wide.
There were just seconds to go to half-time when Murphy's attempted block of a Whyteleafe shot, diverted the ball past his own 'keeper but Swain did well to quickly change direction and grab the ball a yard from the goal line.
It was much the same after the break, with Northwood still looking the more dangerous and likely to score. Otis Williams ran on to a Dwane Williams pass after 51 minutes but pulled his shot wide of the target, and the ex-Rochdale reserve player was looking very sharp up front.
Murphy picked up a knee injurywhich saw the introduction of young Danny Power after 67 minutes, and five minutes later he came close to his first senior goal, latching onto a Yoki corner with a far post strike which flashed just over the bar.
The Woods knew they needed a second goal to be sure of an important and financially valuable victory, and they kept pressing forward. The pacy Gordon was next to go close, pushing the ball through and outstripping the defence but then rolling his shot wide of the post.
It was after 81 minutes that North-wood got their reward, and it was that man Otis Williams who became the hero once again, as more sloppy defensive work saw him catch Adam Broomhead napping and race into the box to fire a shot into the top corner.
It could have got even better for him as well, as four minutes later he latched onto a Dwane Williams flick off a Sonner throw, only to see his shot come back off the post.
In stoppage time he headed a Power cross just over the bar before firing against the post again when set up by Sonner.
The victory earns Northwood a trip to another Ryman Division One South side, Crowborough Athletic, in the next round. The Sussex side were promoted last season, and while they are struggling in the league, they have enjoyed an excellent run in the FA Cup, and are due to play away at Harlow Town in the Third Qualifying Round on Saturday. They beat Eastbourne Town 3-0 in the FA Trophy.
NORTHWOOD: Swain, Holland, Murphy (Power), Orlu, Burgess, Christian, Gordon, Dwane Williams, Sonner, Yoki (Dwain Williams), Otis Williams. Subs not used: Brown, Linehan, Pearce.