Sam Allardyce was relieved that the assistant referee made the right decision as West Ham marked their return to the Premier League with victory against Aston Villa.
Kevin Nolan's disputed goal five minutes before the break handed the Hammers a 1-0 win at Upton Park.
The midfielder tapped-in Ricardo Vaz Te's cross, who was initially flagged offside only for the assistant referee Simon Long to change his mind.
Referee Mike Dean ruled the West Ham striker was onside as Villa defender Ciaran Clark had touched the ball into his direction.
Allardyce told Sky Sports: "I saw it straight away and then I had a quick glance at Mike Dean and saw him pointing to the spot, so I was then delighted because I thought, well, he's given the goal so it's clearly come off the Aston Villa player on the way through to Vaz Te.
"And then of course you've got a little concern because he went over to the assistant referee, but I think it was just a matter to satisfy himself and everybody that he was correct.
"He asked the assistant probably 'why did you give that' and he would have said 'offside' and he'd have said 'look, I know that came off a Villa defender' and so it was the right decision and when you look back at it, it was.
"So, those major decisions, it would have been goalless here right now, rather than one-nil to us had he actually taken the linesman's decision and he'd have got it wrong and it would have been a major decision gone the wrong way for us.
"Because he's got it right, we have to thank him for doing his job really well."