The Croatia international scored his first Hammers goal on his 16 appearance following his move from CSKA Moscow, adding the fourth from the bench as West Ham made light work of Watford.
It may not have been a decisive strike for West Ham as a whole, but it could be a game changer for Vlasic, who has felt the pressure to score since his move, which could cost the east Londoners upwards of £30million after add-ons.
“It is an unbelievable feeling, a relief after three months of struggling,” Vlasic told Standard Sport. “The first one is always the hardest so I think everything will be smoother now.
“It’s hard, it is always hardest to get the first and when you are playing 10-15 minutes in games there is not too much time but it goes down as one, two games more and then it is 13, 14 games without a goal so it is a pressure on you.
“When you score everything is easier so I think everything will be much better now.”
The 24-year-old has hit double figures in his last two seasons when it comes to goals and is now looking to push on and try and replicate that in English football.
“You know for me in the last three seasons the target was always double digits for goals,” said Vlasic.
“It was pretty hard in Russia because there is only 30 games, last two seasons I did that [hit double figures] and I always expect this but we will see if I can make it. There’s not too many games and it depends on my opportunities. We will see.”
Vlasic has worked hard for the Hammers when given his chance, reflected in the fact that goalkeeper Lukasz Fabianski ran the length of the pitch at Vicarage Road to celebrate with the former Everton midfielder.
It was a fitting end to a fantastic 2021 for the Hammers and Vlasic, who will get more opportunities in the coming weeks with Said Benrahma set to join up with Algeria for the Africa Cup of Nations, is confident the club can push on even more in the New Year.
“It is a great feeling [to end the year like this],” said Vlasic.
“Someone told me we have the most points and goals in a year so it is an unbelievable year for the club.
“I am very happy to be part of this club at this moment because before I was always watching West Ham struggling to beat relegation. Now we are fifth, fourth and through in Europe. It is an unbelievable feeling to be part of this now.
“The team can only improve, we are struggling with injuries and these players will be back and we will be even better.”