Leeds climbed top of the Sky Bet Championship as a 2-0 home win against Birmingham extended their unbeaten league start to to seven matches.
The West Yorkshire club were hanging on to a 1-0 lead in the closing stages against Birmingham, courtesy of Samuel Saiz's first-half effort, before substitute Stuart Dallas struck their second in the 90th minute.
But if Thomas Christiansen's side served warning of their promotion credentials in dazzling fashion by despatching Burton at Elland Road on Saturday, they were made to dig deep against Harry Redknapp's side.
Blues belied their poor start to the season under Redknapp - they have won only one of their first seven matches - and will feel aggrieved to have finished empty handed.
Michael Morrison, wearing a mask to protect his broken nose, looped an early header from Jota's corner narrowly wide as Leeds struggled to replicate Saturday's scintillating start against Burton.
Leeds' 5-0 thrashing of Nigel Clough's side ensured another bumper crowd, the first time since 2004 that a midweek league game at Elland Road had been played out before a crowd of over 31,000.
Most of those were soon on their feet when Pablo Hernandez's early effort was headed off the goalline by Cheikh N'Doye before Leeds took a 17th-minute lead.
Pierre-Michel Lasogga's thumping first-time volley from a tight angle was superbly parried by Birmingham goalkeeper and captain David Stockdale, but Saiz pounced to force home the rebound from a yard out for his sixth goal in all competitions this season.
Hernandez volleyed wide soon after as Leeds chased a second, but Birmingham were not ready to roll over.
Two of Redknapp's 13 summer signings, Jeremie Boga, on loan from Chelsea, and fellow midfielder Jota, a B#6million signing from Brentford, provided moments of quality and kept Leeds occupied in their own half.
David Davis fired just wide for Blues in the 38th minute and Leeds right-back Luke Ayling kept his side's noses in front when his brilliant goalline clearance denied Maxime Colin a headed equaliser on the stroke of half-time.
Birmingham continued to test Leeds after the restart. Left-back Vurnon Anita snuffed out more danger when blocking Colin's cut back as anxiety among the home faithful grew.
Lasogga spurned a golden chance to ease Leeds' nerves in the 54th minute. He almost seized on a short back pass, but Stockdale gathered after the German striker appeared to hesitate.
Leeds were dealt a blow when rock-solid skipper Liam Cooper was forced off in the 69th minute. Ayling switched into the middle with substitute Gaetano Berardi on at right-back.
Birmingham substitute Che Adams, on for Sam Gallagher, threatened with a storming run down the left, but his dangerous cross was snaffled by Leeds goalkeeper Felix Wiedwald.
Saiz almost grabbed the game-clinching goal in the 77th minute, but his low shot from the edge of the box was turned away at full stretch by Stockdale.
Leeds fans were left praying for the final whistle as Birmingham continued to probe, but then Leeds broke down the middle and Dallas, an 80th-minute replacement for Hernandez, put the game to bed in the 90th minute.
Lasogga slipped the ball to Dallas and the Northern Ireland international powered a low shot into the bottom corner as Leeds secured their fourth straight league win.