Van Hooijdonk, who reinforced his credentials as English football's leading scorer with his 27th and 28th goals of the season, scored twice in the second half, either side of a strike from Kevin Campbell and a header from Colin Cooper.
Middlesbrough had seemed content to play on the break but their tactics were found to be lacking as Forest, who face their other promotion rivals from the north-east, Sunderland, on Wednesday, were the more inventive and aggressive side.
Van Hooijkonk is incomparable from dead-ball situations. In five free- kicks from outside the box, he scored from one in the 53rd minute, and forced excellent saves from Andy Dibble with the others.
His second goal was also from a dead-ball situation - a penalty after Steve Stone had been tripped by Gianluca Festa. The tall striker hammered the ball straight down the middle.
Campbell grabbed his chance two minutes after the opener, slotting the ball past Dibble after being played onside by Curtis Fleming. Cooper struck in the 75th minute to seal a win which sent Forest top, ahead of Boro on goal difference. He looped a header into an unguarded net after a scramble in the box.
Van Hooijdonk's penalty came five minutes from time and Boro were out on their feet. Marco Branca was substituted by the Boro manager, Bryan Robson, with 20 minutes to go after a frustrating afternoon but his replacement, Alun Armstrong, fared no better. Middlesbrough sorely missed the steadying influence of Andy Townsend, who is serving a suspension, in midfield and, Paul Merson aside, they sorely lacked creativity.
Michael Thomas, on loan from Liverpool, had a game to forget, apart from a booking for a show of petulance, throwing the ball to the ground in disgust after a clash with Andy Johnson.
Goals: Van Hooijdonk (53) 1-0; Campbell (55) 2-0; Cooper (75) 3-0; Van Hooijdonk (85 pen) 4-0.
Nottingham Forest: Beasant; Lyttle, Rogers, Cooper, Chettle, Johnson, Stone (Bonalair, 85), Gemmill, Van Hooijdonk, Campbell, Bart-Williams. Substitutes not used: Thomas, Hjelde.
Middlesbrough: Dibble, Kinder (Ormerod, 66), Fleming, Festa, Pearson, Mustoe, Hignett, Maddison, Branca (Armstrong, 66), Merson, Thomas. Substitute not used: Beck.
Referee: E Wolstenholme (Blackburn).
Bookings: Middlesbrough: Thomas.
Man of the match: Van Hooijdonk.
Attendance: 25,286.Reuse content