Nuno left waiting for first West Ham win after defeat at Leeds
Nuno Espirito Santo criticised West Ham's poor performance as unacceptable, following a winless streak in his first four matches in charge, with Leeds securing a comfortable 2-1 win at Elland Road on Friday evening.
Leeds took the lead through Brenden Aaronson and Joe Rodon within the opening 15 minutes, while Mateus Fernandes netted a consolation goal late on, but it proved insufficient for the underwhelming West Ham side.
Sitting second from the bottom, West Ham remain three points above the drop zone after losing seven of their opening nine Premier League fixtures this term.
Under Nuno, the team has collected just one point from 12 available, starting with a draw against Everton before losses to Arsenal, Brentford, and now Leeds.
West Ham's current four-point haul represents their lowest total at this point in a top-flight season since the 1973-74 campaign, and Nuno commented: "The reason is straightforward. We failed to handle the issues. We overlooked too many aspects.
"We must train diligently and improve significantly. The players seem eager, yet they lose focus at crucial times.
"Such errors are not tolerable in the Premier League. The second half showed improvement, but it falls short when you begin so poorly and face an uphill battle.
"We still have opportunities. It falls to us to maximise the players' potential."
West Ham skipper Jarrod Bowen remarked: "The atmosphere in the changing room is downbeat when you're near the bottom of the table. The only solution is for us to raise our game and display more determination. We require that extra effort.
"We must confront our current position head-on, and we're in a precarious spot right now."
Appointed to succeed the dismissed Graham Potter, who managed the London club for merely eight months, Nuno's mission is to prevent relegation, which would mark West Ham's first absence from the top tier since 2011-12.
Nuno previously parted ways with Nottingham Forest in September amid tensions with outspoken owner Evangelos Marinakis, stemming from disputes regarding transfer strategies.
Should the Portuguese manager fail to reverse West Ham's fortunes swiftly, he risks another sacking within the same campaign.
Leeds' commanding showing highlighted the challenges confronting Nuno.
Just three minutes in, Noah Okafor found space unmarked by young Oliver Scarles, heading the ball which Alphonse Areola pushed away only for Aaronson to poke it in from near the goal line, as West Ham's defence stood motionless.
The visitors looked disorganised, and Daniel Farke's team extended their advantage in the 15th minute.
It proved a dismal goal to allow, with Lucas Paqueta's loose defending permitting Rodon to leap freely and power a header from Sean Longstaff's corner into the net from close range.
West Ham have conceded nine goals from set pieces in the Premier League this season, outpacing every other team by six.
Coping with the relentless rain in Yorkshire, the soaked Nuno adjusted by substituting injured Scarles with forward Callum Wilson, acknowledging the initial setup was ineffective.
Tomas Soucek missed a golden opportunity to reduce the deficit with a misplaced header from close in, amid jeers from the away supporters.
West Ham had never triumphed in a Premier League match after being two goals down at the interval, and this, their 102nd such effort, followed suit.
In the 90th minute, Fernandes nodded home from Jarrod Bowen's delivery into the far corner, yet Leeds held firm through four added minutes to keep West Ham rooted in the bottom three.