A red card helped Leeds United return to winning ways with a comfortable home win over Bristol City.
United had had the better of the match before Josh Brownhill's dismissal early in the second half.
And they made this numerical advantage count.
Kemar Roofe and Pablo Hernandez struck to hand Leeds a vital victory.
Marcelo Bielsa's side were without senior goalkeepers Bailey Peacock-Farrell and Jamal Blackman. Defender Pontus Jansson was also unavailable.
This forced Bielsa to delve deep into United's stocks of precocious young players.
Englishman Will Huffer started in goal and Finn Aapo Halme in central defence. Neither had played a first-team match for the club.
Looking at this, one might have thought that Leeds were in a position of some vulnerability.
But City failed to test the callow pair of prospects as the Whites sought to assert themselves.
With 18 minutes played, the home side had an excellent chance to take the lead.
Mateusz Klich's flighted ball from the right eluded Adam Forshaw.
It instead fell for Ezgjan Alioski, who let the ball bounce before stinging the palms of visiting 'keeper Niki Mäenpää.
Bristol responded. Nicolas Eliasson's free kick was nodded on and Barry Douglas had to head it behind for a corner.
From Hakeeb Adelakun's ensuing corner, Tomas Kalas headed wide.
The visitors seemed content to play on the periphery. They sought to soak up pressure and hit Leeds on the counter. It stood to reason that this negative style struggled to produce chances from anything other than set-pieces.
Huffer punched clear another Eliasson delivery, but only as far as Jamie Paterson, whose lobbed effort dipped over the bar.
Leeds then had another clear-cut chance to break the deadlock.
With half-time fast approaching, City were careless in giving the ball away deep into their half.
Klich then found Roofe in a wide position.
The striker went for glory, but his deflected shot bobbled inches wide of the post.
It was a tepid first half. United, though often slovenly, fashioned two clear chances to score and spurned them. Had they taken either, those present might have reflected upon the half in a more favourable way.
It is sometimes the case in football that a little luck must come one's way if success is to.
Bristol started the second half well. With purpose and vigour, they toiled and countered. Eliasson's deflected shot wrong-footed Huffer before clearing the crossbar. Adelakun fired wide from range after Kalvin Phillips's misplaced pass. Lee Johnson's team were growing into the match.
And then a little luck came Leeds's way.
With 10 minutes of the second period elapsed, idiocy produced opportunity.
Brownhill, already on a yellow card, hacked down Roofe in the middle of the park.
Scott Duncan, the referee, had no other choice but to send him off. All City's endeavour and promise erased. And in a single moment of utter stupidity.
United needed no invitation to capitalise. They introduced Jack Harrison and Samuel Saiz in a bid to make the red card count.
Klich slipped in Alioski, who saw a low shot saved from a tight angle.
Harrison then made his way into the box, but took too long to pull the trigger.
Barry Douglas then arched a stunning, curling effort toward the top corner, only for Mäenpää to make a flying, fingertip save.
Despite this resistance, Leeds would get their goal.
A minute after Mäenpää's heroics, Roofe turned in Hernandez's low shot across goal for his eighth of the season.
And they would make the points safe late in the day with a piece of priceless panache.
With great vision, Saiz lofted a wondrous reverse pass into the box.
Hernandez moved onto it, guiding a deft header past the luckless Mäenpää and into the corner of the net.
This was a crucial victory for United. They may not have been at their best. The red card may have helped them a great deal. But they did enough to get the job done. And, despite the absence of several key players in defence, they limited City to half-chances.
They will now look forward to Tuesday's match at home to struggling Reading, who languish in 20th position.
Leeds United (4-1-4-1): Huffer; Dallas, Halme (Saiz 64’), Cooper, Douglas; Phillips; Hernandez, Forshaw, Klich (Baker 82’), Alioski (Harrison 61’); Roofe.
Unused Subs: Miazek, Davis, Shackleton, Clarke.
Bristol City (4-4-2): Mäenpää; Hunt, Kalas, Webster, Kelly; Eliasson (Diedhiou 62’), Brownhill, Pack, Adelakun (Walsh 62’); Paterson (Eisa 78’), Weimann.
Unused Subs: Pisano, Baker, O’Leary, Dasilva.
Match Statistics (Leeds / Bristol C)
Shots: 20 / 7
On target: 6 / 1
Possession: 63% / 37%
Corners: 10 / 8
Fouls: 7 / 9
Match Details
Referee: Scott Duncan.
Booked: Alioski (Leeds). Brownhill x2 (Bristol City).
Attendance: 34,333.
Man of the match: Kalvin Phillips (Leeds).