Leeds had celebrated promotion to the Premier League on Friday evening when second-placed West Brom lost 2-1 at Huddersfield.
Less than 24 hours later, champagne corks were popping at the Yorkshire club again after third-placed Brentford’s defeat ensured Leeds will go up as champions.
Bielsa’s team, who face Derby today, have two games left and hold a five-point lead over West Brom, who have one match to play.
Brentford’s loss, sealed by Lee Gregory’s first-half goal for Stoke, handed the initiative back to West Brom in the race to join Leeds in the Premier League.
The top two in the Championship go up automatically and West Brom, one point ahead of Brentford, will be promoted if they win their last game against QPR on Wednesday, or if the Bees lose their final match against Barnsley.
Fourth-placed Fulham are also in the hunt, two points behind West Brom after beating Sheffield Wednesday 5-3 yesterday.
Leeds are back in the top flight after a 16-year absence marred by a spell in the third tier, a painful period in administration, a host of woeful owners and 14 failed managers.
Former Argentina, Lazio and Marseille boss Bielsa has awoken Leeds, with crowds regularly over 35,000 at Elland Road before the coronavirus pandemic.
Thousands of fans celebrated on the streets outside their stadium on Friday, with Leeds’ Italian owner Andrea Radrizzani also eager to remember those the club has lost in recent weeks.
Norman Hunter and Jack Charlton two Leeds greats from the Don Revie era in the 1960s and 1970s, died at either end of the recent lockdown. Trevor Cherry, who joined Leeds in the early 1970s and won a league title, passed away in between.
The trio made making a combined 1,985 appearances for the club.
Celebrating the club’s centenary last October, Hunter wrote Radrizzani a letter expressing his wish that the club would be promoted in his lifetime.
“A word about Norman Hunter and Jack Charlton, two club legends we lost recently and who would have certainly celebrated this achievement with us,” he said in a letter on Leeds’ website.
“They are part of a great legacy that we will work hard to honour, as we continue to take strides forward in a new cycle for this fantastic club.”
Radrizzani assumed sole control of Leeds in 2017, having initially gone through a staged buy-out from the unpopular Massimo Cellino.
After a false start under Thomas Christiansen and then a short spell under Paul Heckingbottom, Radrizzani and director of football Victor Orta pursued Bielsa.
The Argentine has delivered, transforming a mid-table team into champions in just two seasons.
“I am so happy for everyone in the Leeds United family, we all deserve this promotion,” Radrizzani said.
“Leeds United is one of England’s greatest and most well-supported clubs with a rich history known all over the world.
“We have been out of the top flight for 16 years and I am thrilled for the whole club and our incredible fans that we are back in the Premier League...
“Since my journey with Leeds United began in the summer of 2017, we have strived for this moment and it is a time for us all to celebrate the club returning to where we belong.”
Elsewhere in the Championship yesterday, Cardiff held onto sixth place in the fight to reach the play-offs.
Cardiff won 3-1 at Middlesbrough and need a point from their last game against Hull to finish in the top six.
Their local rivals Swansea are seventh, three points behind after beating Bristol City 1-0.
Third bottom Luton beat Hull 1-0 to stay in the hunt to avoid relegation, with the Hatters sitting behind fourth bottom Charlton on goal difference.