Leeds Rhinos coach Brian McDermott has admitted that his team's record 50-0 Challenge Cup final victory over Hull KR had caught up with the players as they were beaten 32-18 by St Helens.
The league leaders were physically dominated by a Saints side coming off the back of a week's rest.
"I thought Saints played very direct and aggressive," McDermott told reporters.
"There was too much dropped ball near their try-line and, as the game started to bite, too many fellas dropped off tackles.
"Defensively I thought we were solid for the most part, but as we got tired, which we thought we would, we started to drop off."
The defeat allowed Wigan Warriors to cut Leeds' lead at the top of Super League to two points with a 42-16 win over Catalans Dragons