Diafra Sakho came off the bench to fire West Ham United to a last-gasp 1-0 home win over Swansea and save Slaven Bilic from a fresh wave of scrutiny.
Senegal striker Sakho bundled in a killer 90th-minute cross from fellow substitute Arthur Masuaku to secure a vital second victory of a difficult Premier League campaign to date.
The Hammers had looked short on attacking ideas throughout a frustrating afternoon and the second-half substitution of Javier Hernandez was greeted with boos by the home fans, but they were soon in raptures as Bilic's gamble paid dividends.
Under pressure after taking just one win from six league outings, the Hammers boss partnered Hernandez and Andy Carroll in attack in an attempt to outgun a goal-shy Swansea.
But it was the Swans who settled the quickest into their new 4-4-2 as Paul Clement's move to a diamond midfield resulted in a several tidy passing moves in a subdued first half.
The second half continued in a similar trend until Sakho's timely intervention, ruining what would have been the visitors' first away clean sheet against West Ham.
Michail Antonio passed a late fitness test to start on the right of a four-man midfield and the winger looked lively early on, forcing Lukasz Fabianksi to claw a miscued volley away from the top-left corner.
Swansea joined the hosts in fielding two out-and-out strikers and a swerving effort from one of that pair, Wilfried Bony, drew a strong hand from Joe Hart in the 15th minute.
Pablo Zabaleta then produced an important block to spare his goalkeeper from more work as the Swans began to turn their dominance of possession into an attacking threat.
The visitors did receive a let-off just prior to the half-hour mark when Renato Sanches, who was dropped for last weekend's 2-1 defeat against Watford, escaped with only a yellow card for a late, studs-up challenge on England full-back Aaron Cresswell.
After Fabianksi collected a tame Andre Ayew header, both sides had reasons to welcome the end of a tepid first half.
Carroll seemed destined to break the deadlock when Antonio dropped an inviting cross to the far post, but the ball just evaded the forward's outstretched left boot.
Bilic called Manuel Lanzini from the bench just after the hour in search of more creativity, although West Ham's growing momentum was momentarily halted when Fabianski required treatment following a heavy fall.
With both sets of forwards failing to fire, Swansea left-back Martin Olsson almost surprised Hart when his clever right-footed attempt curled narrowly around the left upright.
But, after Carroll struck the crossbar from one fine Masuaku delivery, the left-back repeated the trick in flashing a low ball across the face for Sakho to gleefully tuck away.