Former Inter midfielder Cambiasso put through his own net in strange fashion just after half-time at the King Power Stadium on Saturday to gift the visitors maximum points.
Wes Morgan's attempted clearance bounced back off Cambiasso, and Leicester are now five games without a win in the Premier League.
Conversely, West Brom have now lost just once in their last six top-flight outings - with Irvine grateful to take goals in whatever form they arrive.
"I'm absolutely delighted with the result and I'm quite happy to take goals like that," he said.
"It was fortunate the way it went in but it was a good move in order for us to get there.
"I'm delighted with the result when you consider that Manchester United, Arsenal, Everton [and] Burnley have all been here and none of them have won.
"It was always going to be a difficult place to come and while it wasn't the way I would have anticipated getting the victory, it was certainly welcome."
After a difficult start to West Brom's campaign, Irvine's tenure is now beginning to look more positive - despite their midweek defeat to Championship side Bournemouth in the League Cup.
And having seen Cristian Gamboa and Silvestre Varela return to training in recent weeks, Irvine feels his squad is now starting to take shape.
Asked what had inspired West Brom's upturn, Irvine responded: "Getting to the situation where we've got a proper group to train with.
"Everyone is starting to get to know each other, being able to get a settled team and being able to do a lot of quality work on the training ground.
"All those things are a reflection on how our players go about their jobs. They're a great group to work with and they work really hard every single day.
"They're starting to get their rewards for that."
