Roberto Martinez felt his Swansea side were taught a "cruel lesson" after 10-man Sheffield United grabbed a 1-1 draw at the Liberty Stadium.The hosts had taken the lead in the 56th minute when Jason Scotland rammed home a penalty but they spurned a number of golden opportunities to make the game safe before Chris Morgan's 86th-minute strike.

"It is hard to explain how we ended up drawing the match and it is a big blow for us," said Martinez.

"We are very proud of the way we have adapted to the Championship this season but a lack of experience has cost us today after we created enough chances to at least score a second goal.

"I am very pleased with our performance, although I do think the sending-off went against us. They were very well organised after that but we limited them to just a couple of opportunities.

"Although we have gone six matches without a win we have now drawn five in a row but today was a cruel lesson for my players."

The game hinged on two decisions in less than 10 minutes from West Midlands referee Andre Marriner.

After dismissing Darius Henderson 30 seconds into the second half for an alleged elbow on Swansea's Spanish full-back Angel Rangel, he awarded the Swans a penalty even though Gary Naysmith's challenge on Scotland looked just outside the area.

The Swans piled on the pressure after going ahead and with Leon Britton and Joe Allen running midfield, they made scores of chances to add to their slender lead.

Unfortunately they found Blades keeper Paddy Kenny in superb form, particularly in a double stop from Tom Butler and then Scotland.

Blades boss Kevin Blackwell pushed on two strikers to replace two of his tiring defenders and it worked perfectly with that late equaliser.

Blackwell failed to appear after the match, leaving deputy Sam Ellis to air his thoughts.

"We made it hard work after the sending-off and our game plan went out of the window, but I am not here to criticise the referee," he said.

"Certainly it was a point grabbed at the end of the day and that makes if four from two games so we are still on course."

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