Martinez's side had played so well in beating fellow strugglers Reading 3-0 last week, but Stewart Downing opened the scoring with a second-minute header and Suarez took his tally in the Premier League to 21 - 28 for the season.
From the moment Downing put the visitors ahead it was virtually one-way traffic - apart from two brilliant saves by Jose Reina - as Suarez created havoc.
"The first goal showed a real lack of concentration as Downing had a free header in the six-yard box," Martinez said.
"The first 20 minutes we were very soft and defensively nowhere near where we needed to be.
"That (first) goal had a snowball effect on our performance."
Martinez denied not having a method of negating the threat of Suarez cost them dearly.
"If you look at the stats at the end we had as many shots on target as they had but the performance of Pepe Reina had a bigger effect on the result than us stopping Luis Suarez," he added.