Watford kept their faint play-off hopes alive with a 1-0 home win over Barnsley.
Boss Malky Mackay was impressed with the manner in which they held on for the victory after taking a first minute lead.
He said: "I thought we started very well. We've been guilty in the last few weeks of possibly losing goals early on in games and I think to score so early on was fantastic.
"We also had a couple of chances right after to go further ahead so it was great to get a good start to the game.
"We knew it was going to be a tough day for us. We had Norwich and Leeds during the last 10 days and you're playing two of the top teams in the division, but this was going to be as important as any of them because it's a team where if you don't compete with every ball they can knock it about and come at us and that's what they did do.
"I knew they were going to come at us (in the second half) and it was resilience and character that got us through that second half.
"I'm sure Mark (Robins) will feel he's played much worse than that this season and won games, but we're all alike and from my point of view I've just said to the players it's their team spirit and togetherness as a group this season at the training ground every day that saw that game out."
Barnsley chief Mark Robins was left to rue his side's slow start and the lack of a cutting edge.
He said: "What was it (Eustace's goal)? 45 seconds, something like that. I thought we learned our lesson from the last game against QPR.
"Unfortunately we hadn't, they've not picked up properly and they've (Watford) got a habit of starting quickly and they've done that again today and won the game inside the first 45 seconds.
"Objectively we've done enough to win the game. What we haven't done is the all important thing and hit the back of the net with the ball.
"I think we've had upwards of 15 shots and 14, 15 corners and not managed to make one of those count.
"That's the disappointment. We've created enough to win three, four games but not done enough and hit the back of the net.
"There's been some great balls gone in, especially from Reuben Noble-Lazarus when he came on and with Matty Hill and Kieran Trippier.
"The ball's in the right area often enough, surely there's going to be somebody that gambles across a defender and gets even a lucky scrape off them but we haven't done that. That's the disappointment."