Irish were second best in the first half and went into the break trailing by 14 points, but two yellow cards for Quins allowed Smith's side to battle back to a 20-15 defeat.
Despite missing out on an opening-weekend victory, Smith was pleased with his side's response to such a difficult first 40 minutes.
"It was a classic game of two halves, we couldn't get going in the first 20 minutes and they rattled up the scores," he told reporters.
"We had got to half time without firing any shots and were outplayed in the first half but we reassessed at the interval and ultimately had a shot to win it.
"They are a quality outfit so at half time I would certainly have taken a bonus point."
Irish failed to cross the line throughout the match, with all of their points coming from the boot of Shane Geraghty.