Four were at the hands of the world champion All Blacks, but Saturday's 31-28 loss to South Africa extended England's worst run since 2006 and Lancaster knows there are no excuses.
If his team really are going to have a crack at winning the World Cup on home soil in less than a year's time, then they need to start finding a way to win tight games -- and soon.
They showed admirable tenacity to fight back from 20-6 down against South Africa to level the scores at 20-20 with two rolling-maul tries right out of the 1970s Twickenham playbook.
But they were unable to complete the turnaround as the Springboks scored their own try from a rolling maul and edged far enough clear to make Brad Barritt's late try almost irrelevant.
South Africa remain the only major nation Lancaster has yet to beat but the more damming statistic is that he has managed only two wins in 13 matches against the southern hemisphere big three.
The coach, however, remains convinced that his team are on an upward trajectory.
Jon Serfontein (South Africa) against England
Image credit: Icon Sport
"When we took over we knew we had to take a young group of players through some tough environments," he told reporters.
"But we are not going to feel sorry for ourselves. I believe in what we are doing. The players are being tested at the highest level and a lot of them are turning up.
"We will not panic, we will not deviate and we won't lose our nerve."
It was stirring stuff from Lancaster and, in truth, his team could easily have won the game.
They gifted the Springboks points with an interception try and silly penalties, while spilling much of their own ball in good positions.
The two tries they scored on the back of unstoppable rolling mauls had the home fans roaring and will have sent shudders down the spines of opposition coaches.
South Africa captain Jean de Villiers believes that England are not too far away.
"This England side is a team on the up," he said. "We got points on the board but they could have beaten us today."
Coach Heyneke Meyer agreed.
"They will be better for this and I think they can have a great World Cup," he said.
"Maybe we can meet them in the final at Twickenham."