Goalkeeper David Martin was “in tears” after a debut where West Ham ended a seven-game winless run with victory at Chelsea.
Martin, the son of Hammers legend Alvin, was picked by boss Manuel Pellegrini instead of Spanish keeper Roberto, who had conceded nine goal in three games.
And it proved an inspired choice as the visitors kept a first clean sheet since 22 September and achieved a first victory at Chelsea for 17 years.
Aaron Cresswell scored the winner three minutes after the break as he cut inside and fired low past Kepa Arrizabalaga.
Chelsea had plenty of chances early on as Christian Pulisic missed the target from a few yards out. The American also wasted a great opportunity late on.
But West Ham relieved the pressure on Pellegrini as 33-year-old Martin also made it a Premier League debut to remember.
The former Millwall and MK Dons keeper sank to his knees before celebrating in the stands with his father, who played in the West Ham defence for 21 years.
“It still doesn’t feel real,” said Martin, who is a boyhood fan. “I’m just pleased I got through it, I didn’t let anyone down and actually I enjoyed it in the end.
“My dad didn’t say much – I think we were both in tears. For my dad to play for the club for 21 years and see it, and for me to make my debut, keep a clean sheet and get win for the boys, it is so pleasing.
“I was struggling to eat for two days; Cressa [Cresswell] was laughing at me because my plate was taken away because I couldn’t eat my food.
“I hope I’ve given myself a good chance [to keep my place] but I have to work hard and keep grounded.”
Victory lifted West Ham four points clear of the relegation zone while Chelsea failed to close the three-point gap to second-placed Manchester City and Leicester City in third.
Emotional Martin helps engineer win
Third-choice keeper Martin came into the side after a woeful run of form by Roberto, which had contributed to the Hammers slipping to one place above the relegation zone before kick-off.
A lack of confidence in the Spaniard seemed to be affecting the team, who had not kept a clean sheet since their last Premier League win – against Manchester United – more than two months ago.
And prior to the game at Stamford Bridge, there were some reports that Chilean Pellegrini had two games to save his job.
But Martin, who was also on Liverpool’s books early in his career, seemed to lift his defence as the likes of centre-back Fabian Balbuena were in fine form.
Despite his nerves in advance of such a momentous occasion, the nerves did not show during the game as he made a fantastic double stop to deny Mateo Kovacic and Oliver Giroud.
And he was roundly cheered during the match by the West Ham fans, who had booed Roberto during the 3-2 defeat by Tottenham last Saturday.
The visiting supporters were delirious when they thought their team had gone 2-0 up after 69 minutes, before Michail Antonio’s goal was ruled out after a VAR review for handball.
But it proved a mere footnote at the final whistle, as Martin was surrounded by his team-mates and began to let a career highlight sink in.
’Picking Martin was a risk’
West Ham boss Manuel Pellegrini: “It was very difficult [to drop Roberto]. It’s a position you must be very careful of when you change it. I gave him the most amount of matches you can as a manager, but at the moment we needed a reaction.
“It was a risk with Martin because he had never played before in Premier League but he did very well. They are a complete team and the defenders helped him a lot to keep a clean sheet.
“It was a very important win, because we have had results that are not expected or deserved. You must be solid and consistent. That was the major change that we did compared with other games and it allowed us to keep a clean sheet and beat a team like Chelsea who are in a very good moment.”