London - Leeds moved to the top of the Championship as late goals from Eddie Nketiah and Mateusz Klich secured a 2-0 win at Barnsley on Sunday.
Swansea's defeat to Nottingham Forest on Saturday opened the door for Marcelo Bielsa's men to claim top spot as they look to end a 15-year wait to return to the Premier League.
However, they were made to wait in a hard-fought Yorkshire derby until Arsenal loanee Nketiah came off the bench to make the difference.
The 20-year-old turned home Kalvin Phillips's free-kick eight minutes from time and was then upended in the box to allow Klich the chance to seal all three points from the penalty spot.
Leeds edge ahead of Swansea on goal difference at the top of a congested Championship table with just three points separating first from eighth.
Earlier, Garry Monk won the battle of two new managers in another Yorkshire derby as Sheffield Wednesday beat Huddersfield 2-0 John Smith's Stadium.
Steven Fletcher's 10th-minute header and a rare goal from substitute Sam Winnall separated the sides as Monk celebrated his first game in charge in style.
"It wasn't perfect, but for a first attempt at some of the stuff we were asking, it was very good," said Monk. "I'm very pleased."
Huddersfield remain second bottom with just one point from their opening seven games after relegation from the Premier League last season.
Former PE teachers Danny Cowley, along with assistant boss and brother Nicky, have been handed the tough task of lifting the Terriers after impressing at League One Lincoln.
"We saw a football club that's hurting and a team that's hurting," said Cowley, after Huddersfield's wait for a first league win since February continued.
"What we have to do is try to help them - technically, tactically, physically and psychologically.
"They need my help and not criticism at this point. In the short-term, we need to get back to basics."