The Baggies coach took full control of the club this summer, moving into his first management work in the Premier League league following spells with Preston, Sheffield Wednesday and Everton’s Academy set-up.
Having suffered a slow start to the season, with two draws and two defeats in their opening four games, the Baggies finally claimed their first three-points of the season with a surprise 1-0 victory over Spurs at White Hart Lane - their first win in North London since 1984.
James Morrison scored a late winner to round off a well-worked display, and Irvine told Goal.com that recording a first win was his best day in management.
The 56-year-old said: "It's my most satisfying day in management for West Bromwich Albion.
"It's great to get that first win. Everybody makes such a big thing about it.
"I'll go back to that first game against Sunderland, when it looked like we were going to get that win on the first day and that would have avoided all the questions – so I suppose it puts that question to bed.
"But we can't rest on that, we have now got to back that performance up by getting other good results."
Irvine finally was allowed to select Joleon Lescott, having joined from Manchester City during the summer, overcoming fitness concerns to make his debut for the Baggies. Despite wanting to include Lescott at an earlier date, Irvine knew that rushing the central defender back would be a bad idea, and the coach was rewarded with a clean sheet upon his introduction.
"We would have been taking a big risk if we put him in before he was ready,” he continued. "We already had one set-back against Nottingham Forest.
"I have tried to keep saying to people that we want to put him in the team but we want to put him in the team when he is ready and we felt as if he was ready this week."