Sri Lanka collapsed to 55 all out inside 20 overs as India made it seven wins out of seven at the tournament with a colossal 302-run triumph in Mumbai on Thursday.
Their top-order had no answers as Jasprit Bumrah and Mohammed Siraj reduced then to 3-4 before the remorseless Mohammed Shami followed up with 5-18 in five overs.
Iyer, who had earlier starred on his Wankhede Stadium home ground with a blistering 82, including six sixes, told reporters: "Looking at today's bowling and the previous game, definitely, we are lucky not to play against them.
"But at the same time, we bat against them in the nets. So, it gives us an added motivation to come and play any sort of bowlers."
Iyer's innings was his highest score of the tournament after he had failed to make the most of some promising openings.
"It was playing on my mind right from the start, because I was getting tremendous starts in the first few games," he said. "I just wasn't able to capitalise.
"But today, I just told myself that if it's there in my area, I'm just going to go take the bull by the horns.
"Fortunately, it worked for me and I hope that it keeps on working for me in the future as well, because the team is in a great space at the moment."
- 'Play for the team'
Virat Kohli, a member of the India side that beat Sri Lanka in the 2011 World Cup final at the Wankhede, made 88 on Thursday.
That left him still one short of equalling Sachin Tendulkar's world record of 49 one-day centuries, with opener Shubman Gill out for 92 in a total of 357-8.
But Iyer was unconcerned by the lack of a hundred, saying: "This is the stage where you play for the team. You don't play for your individual performances."
Sri Lanka's fifth defeat in seven matches ended the 1996 champions' semi-final hopes, with Tigers' assistant coach Naveed Nawaz lauding India's pace trio.
"Bumrah, Siraj, and of course Shami, they're very skilful. They always get the batsman to play the ball, and the ball's always attacking the stumps.
"They all can swing the ball both ways and also, we have seen their death over skills, the middle overs as well as the death."
With the top seven sides in the 10-team World Cup, plus hosts Pakistan, qualifying the 2025 Champions Trophy, Nawaz said Sri Lanka still had something to play for in their concluding pool games against Bangladesh and New Zealand.
"I think it's going to be important that we finish above eighth to qualify for the Champions Trophy."
He added: "We had the same issue in June when we played the World Cup qualifiers.
"We will get the boys motivated and see what we can do in the next two games to bring out our best cricket."
