Facing his former club for the first time, Lampard earned a point for 10-man City with a neat 85th-minute equaliser in the 1-1 draw at Etihad Stadium.
It meant Premier League leaders Chelsea failed to take full points for the first time this season, but they stayed three points clear at the top.
Kompany said he understood how big an impact Lampard's goal could have on the title race.
"Ever since I've been at this club, seasons and big moments have been decided on small events like this, so I will never underestimate what it could mean to our season," he said.
"Frank has brought experience - experience is not just a word you make up, it's really something that helps, like the goal he scored.
"It means keeping your head cool when you're under pressure and we're down to 10 men. How many players would've scored that goal? That's what he's proven in only a few minutes."
Lampard is on loan in Manchester until January, when he returns to parent club New York City.
Kompany said the stint was ideal for all parties.
"He needed what we can offer him and we need what he can bring to us as well, so both ways," the Belgium defender said.
"If you talk to him I reckon that's how he sees it as well."
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