London Irish forwards coach Glenn Delaney admitted his side had failed to take their opportunities after going down 17-16 at home to Leicester in their opening LV= Cup fixture on Saturday.
The Tigers were second best in terms of territory and possession for much of the match, but they took their chances to secure the narrow victory at the Madejski Stadium.
"We are very disappointed as we wanted to secure a win," Delaney said. "We had complete dominance up front, had more possession and greater opportunities."
Irish could only manage one try, scored by Guy Armitage, with Myles Dorrian kicking three penalties and a conversion.
They squandered a number of chances, with frequent poor handling preventing them from scoring more tries.
"The game was there for the taking, but we needed to be 20 per cent more clinical, 20 per cent sharper and 20 per cent more accurate at the breakdown," Delaney added.
The more clinical Tigers scored two tries through Miles Benjamin and Robert Barbieri, with Tommy Bell converting both and kicking a penalty.
Tigers director of rugby Richard Cockerill agreed that it was vital for his side to turn in a decent performance after last week's disappointing defeat against Scarlets.
"The result was important for us as to put in all that work and lose would have been tough," he said. "It was a competitive game and could have gone either way, but our defensive commitment sneaked it at the end."
Leicester had to overcome the loss of front-row replacements Harry Thacker and Riccardo Brugnara though injury and the setback of two yellow cards for Adam Thompstone and Tom Bristow to record their hard-fought success.
"Irish posed threats all over the field but our lads put their bodies on the line," Cockerill added. "They are a very inexperienced group as they brought the cavalry on and we brought the academy on."