Adam Armstrong hit a late winner as Southampton claimed their first Premier League victory of the season by beating Everton at St Mary's.
Just 25 seconds after Beto hit the crossbar at the opposite end of the pitch, Armstrong fired in from Yukinari Sugawara's pass with five minutes remaining in a dramatic conclusion.
Substitute Beto, who scored a stoppage-time equaliser against Fulham last weekend, thought he had once again rescued his side in the 89th minute - but after a lengthy video assistant referee (VAR) check the goal was disallowed for offside to huge cheers from the home supporters.
Aaron Ramsdale had produced two excellent second-half saves to keep Russell Martin's side level, first pushing Orel Mangala's powerful drive over with a strong hand before preventing Michael Keane's diving back-post header from sneaking into the bottom corner.
Southampton failed to register an attempt in the opening 40 minutes, despite dominating possession, but the hosts had two great opportunities to break the deadlock at the end of a largely uneventful first half.
First Cameron Archer went close to finding the bottom corner following a slick passing move, before Taylor Harwood-Bellis headed marginally wide from a corner.
The home side carried much more of a threat in the second half in pursuit of a desperately needed first victory and eventually got their reward when Armstrong beat Jordan Pickford to lift Saints off the bottom of the table.
Everton boss Sean Dyche was aggrieved that Jan Bednarek's yellow card was not upgraded following a 77th-minute VAR check after he halted Beto's charge towards goal, but his side remain 16th with defeat.
Relief as Saints end wait for win
At the end of a breathless conclusion at St Mary's, the overwhelming feeling was one of relief.
The home fans at last had something to celebrate after a difficult return to the top-flight which had seen Saints endure their longest winless run from the beginning of a league campaign, and manager Martin could not hide his delight as he celebrated with his staff at the full-time whistle.
After losing their opening four matches, Everton arrived at St Mary's unbeaten in their past five following Beto's 94th-minute leveller against Fulham, having rediscovered their ability to grind out results.
That is an art which Southampton - winless and with just one point to show from their first nine games - are well aware they must quickly master.
Praised by Manchester City boss Pep Guardiola after stubbornly sticking to their principles of executing pleasing, passing football in a 1-0 loss to the champions last week, here they got across the line to earn a result they will hope can kickstart their season.
The first 40 minutes epitomised Southampton's start to the campaign, failing to register an attempt on Pickford's goal despite averaging around two-thirds of the possession.
Everton pressed aggressively as Saints persevered with playing out from the back in a first half disrupted by stoppages and the visitors' direct approach initially appeared more likely to bring reward, although the Toffees were unable to take advantage when Dwight McNeil dispossessed Flynn Downes inside the penalty area.
With Ramsdale to thank for protecting the clean sheet, Southampton's belief grew in attack and eventually Armstrong was able to seize his moment - one which could prove hugely significant in the context of his side's season.
The home fans were not able to completely enjoy the remaining minutes, but the decision to disallow Beto's late equaliser was cheered as loudly as Armstrong's goal, before Southampton held on to end a 22-match winless run in the top-flight.
"It's a big relief. I have happiness, pride and gratitude with the players, the staff, owners and the board. It's been a tough period," said Saints boss Martin.
"The guys stuck with it. They're an amazing group, I love being here and I want to drag it out for as long as I can. Some of the football we played today was outstanding."
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