Marcelo Bielsa felt Leeds had taken a "step forward" to winning promotion after Pablo Hernandez's late winner secured a 1-0 victory at Swansea.
On a day when Leeds paid tribute to club great Jack Charlton, Bielsa's side moved to within four points of ending their 16-year wait to play in the top flight of English football.
Championship leaders Leeds are now three points ahead of second-placed West Brom, and six clear of in-form Brentford, with games against Barnsley, Derby and Charlton to come.
"I can not enjoy this," Bielsa said. "What you feel just is that you are taking a step forward. The only thing I can enjoy is the last objective, if we get it.
"The match was very close, very narrow, few chances. When the match progressed our possibilities were growing and in the last 30 minutes I think we deserved to score and to make the difference."
In a game of few chances prior to substitute Hernandez's late strike, Leeds had the best opportunity after 64 minutes.
Patrick Bamford failed to head home from six yards, allowing Swansea goalkeeper Freddie Woodman to palm away his effort.
But Hernandez, who played for Swansea for two years between 2012 and 2014, proved the hero by rolling home Luke Ayling's cross off a post.
Stoke eased their relegation worries with a comfortable 2-0 win over fellow strugglers Birmingham. Danny Batth and Sam Clucas both scored during an impressive first half as the Potters climbed above the Blues in the table.
James McClean could have got his name on the scoresheet but hit the woodwork. The win gives Stoke back-to-back home victories and gives them a four-point cushion on safety.