Huddersfield went into the fixture at Stamford Bridge requiring one point from games with the Blues and Arsenal, but the Terriers produced a resilient display in West London to earn a share of the spoils.
The Yorkshire outfit had been odds-on favourites to return to the Championship, but Wagner has paid credit to the "mental strength" of his squad, who also held champions Manchester City at the Etihad Stadium on Sunday.
The 46-year-old is quoted by Sky Sports News as saying: "My English is not good enough to give the players the credit they deserve. If you have the passion, desire and spirit you can compete with top top quality and you saw today that we can do it. We had luck, no doubt about it, but if any players deserve it, it's this set of players.
"I never doubted their mental strength. We have so many experiences, the playoffs, the final, some very big dips in the season, five defeats in a row. We have always come back. In this very exciting week with proper Premier League fixtures we have confirmed everything, we have done it. I am so unbelievably proud.
"I was shocked that we had the lead. People said we had no chance, I will not criticise one of them because they were right. We were everything but a Premier League club last summer but we have given it a go. We have showed everybody that we are humble but we are ambitious. That is the town, and the club."
Huddersfield can still finish as high as 15th place in the top-flight standings.