VIDEO: Reds were 'more hungry' says Lions coach
The Lions, who were favourites heading into the encounter, went down 22-27 after trailing 0-24 at the half-time break.
The result was a big blow to the Lions after they started their tour with an emphatic 29-0 win over the Waratahs in Sydney a week earlier.
"With our group, I am always positive. It was a good comeback [in the second half] but it is not good enough," said De Bruin.
"We didn't start well enough. The fact that we didn't start well was the reason we lost.
De Bruin said the Reds were hungrier for the win
"They played very well, they were hungry. They were almost desperate than hungry.
"I have been in this game many years and I know when a team is hungry. I said it to the assistant coach next to me that they are just more hungry.
"They hit the rucks harder. They were first at the breakdown. Every time when there was a pressure situation I saw more hunger from them than from us," De Bruin added.
Lions captain Francois Mostert agreed with his coach's sentiments.
"I must give credit to the reds. I think they wanted it more than us in the first half," said Mostert.
"I think some of our guys didn't do their job, but we will go back this week and work on it and hopefully we can make our supporters proud again next Saturday."
The Lions face the Hurricanes in Wellington in Round 12.