Huddersfield Town lost their 100 per cent home record as Fernando Forestieri's second-half penalty swung a tight Yorkshire derby in Sheffield Wednesday's direction.
Forestieri kept his cool to slot his 67th-minute kick past Danny Ward after a handball by Rajiv van La Parra.
Wednesday's Italian ace had earlier hit a post while Town's Elias Kachunga later had a header cleared off the line.
The Sky-televised game was played in front of 22,368, Town's highest-ever league gate at the John Smith's Stadium.
WATCH: Doug Thomson and Blake Welton preview Huddersfield Town vs Sheffield Wednesday
First Half
4 mins: Nervy moments after a Wednesday corner, but David Jones' cross glances the bar and Town survive.
12 mins: Neat Town move as a Christopher Schindler ball releases Nahki Wells for a cross, but the ball is cleared.
13 mins: Town keeper Danny Ward races from his area to clear from Fernando Forestieri.
25 mins: Wells glances a header across the face of goal.
29 mins:Kasey Palmer's header is held by Wednesday keeper Kieren Westwood.
32 mins: Westwood holds an Elias Kachunga shot at the second attempt.
33 mins: Westwood saves Palmer's low shot.
44 mins: Town skipper Mark Hudson makes a key clearance from a Kieran Lee delivery.
45mins:Tommy Smith's cross is deflected into the side-netting.
WATCH: Doug Thomson and Blake Welton on Huddersfield Town v Sheffield Wednesday at Half Time
Second Half
48 mins: Forestieri lofts a shot against the right-hand post.
53 mins: Rajiv van La Parra's cross forces Wednesday defender Sam Hutchinson into an acrobatic headed clearance.
60 mins: Town left-back Chris Lowe curls a free-kick just over.
67 mins: Forestieri fires Wednesday in front from the penalty spot after van La Parra is ruled to have handled a Tom Lees shot.
73 mins:Aaron Mooy drives a free-kick into the Wednesday wall.
75 mins: Town substitute Jack Payne's shot is blocked.
77 mins: Smith does enough to thwart Gary Hooper, whose close-range header is defected off course.
80 mins: Kachunga's header from Lowe's corner is cleared off the line by Hooper.
90 mins: Ward saves from Wednesday's Liam Palmer.
Line Ups
Town: Ward, Smith, Hudson, Schindler, Lowe (Hefele, 84), Mooy, Hogg, Van La Parra, Palmer (Payne, 70), Kachunga, Wells.
Unused Subs: Whitehead, Bunn, Holmes-Dennis, Cranie, Coleman.
Wednesday: Westwood, Palmer, Pudil, Lees, Hutchinson, Bannan (Wallace, 57), Jones, Lee, Reach, Forestieri (Nuhiu, 84), Hooper (Loovens, 90).
Unused Subs: Abdi, Hunt, Buckley, Dawson.
Referee: Graham Scott (Oxfordshire).