Marcelo Bielsa's Leeds had been held to back-to-back draws ahead of Sunday's (AEDT) match, but a goal in each half from Tyler Roberts and Jack Harrison lifted it to the summit.
At the opposite end of the league, Jonathan Woodgate remains under pressure after Middlesbrough's 2-0 loss at Derby County, with Tom Lawrence scoring both goals.
Luton Town and Wigan Athletic also remain in trouble after losing to Nottingham Forest and Swansea City respectively on a dramatic day of Championship action.
With West Bromwich Albion not in action until Tuesday (AEDT), the chasing pack knew it had a chance to capitalise.
Swansea was first up in the early kick-off and followed up its 1-0 derby win over Cardiff City last time out with a late 2-1 victory at Wigan to temporarily move top.
Sam Surridge's late header snatched all three points for Swansea after Kieffer Moore had cancelled out Nathan Dyer's opener from the penalty spot.
However, the Welsh side dropped down to second a few hours later after Leeds's home win, Harrison adding to Roberts's first goal of the season.
Having had its game with Reading called off last week because of bad weather, Nottingham Forest put its fresh legs to good use by opening a two-goal lead at Luton Town.
Callum McManaman pulled one back late on for strugglers Luton, but goals from Lewis Grabban and Sammy Ameobi proved enough to move 2-1 winner Forest from 10th to fifth.
Sheffield Wednesday remains outside the top six after going down 2-1 to Blackburn Rovers, all three goals at Ewood Park coming in the final seven minutes.
Jacob Murphy made the breakthrough for the Owls, only for Tosin Adarabioyo and John Buckley to net in quick succession to end Blackburn's six-match winless run.
The Championship's lowest scorer fired another blank — its fourth in a row — with Derby winger Lawrence's brace at Pride Park leaving under-fire Woodgate with two wins since becoming Boro boss.
Elsewhere, Huddersfield Town opened up a four-point gap on the relegation zone with a Karlan Grant-inspired 1-0 win at fellow in-form side Brentford.
Grant broke the deadlock just after the hour mark at Griffin Park to snap Brentford's three-match winning streak and continue Huddersfield's resurgence under Danny Cowley.
Meanwhile, Reading beat fellow struggler Millwall 2-1 through first-half goals from Jordan Obita and Sam Baldock to give themselves some breathing space.
Hull City picked up a third league win in a row with a clinical 3-0 victory over out-of-form Fulham, which has won just one of its past five matches.
A first goal in senior football from Josh Bowler gave Hull the lead and further goals followed from Jarrod Bowen and Tom Eaves after the break.
Grant McCann's ever-improving side are now in 11th place, one point better off than Cardiff City, which was a 4-2 winner over Birmingham City in south Wales.
Joe Ralls scored a hat-trick in an eventful contest that ended with both teams reduced to 10 men, with Danny Ward and Harlee Dean the players to see red.