England, who were already guaranteed to finish top of Group D after wins over Argentina, Japan and Chile, opened brightly in Lille with a try by lock Ollie Chessum and a penalty from Owen Farrell, which took the captain past Jonny Wilkinson's points record for England.
"What a player he is," said a relieved England coach Steve Borthwick.
"I know everyone is going to talk about kicking the points but what a phenomenal player and leader.
"He was integral today leading this team through a very difficult (game) through a performance that was very scrappy to get a win. A great player and leader."
Samoa, who have sputtered through the tournament with defeats by Japan and Argentina, sparked into life however, with two thrilling tries from wing Nigel Ah-Wong.
Playing with real passion, pace and power, the Samoans had finally shown up at the World Cup and they might have had a third try but Duncan Paia'aua's effort was ruled out by the TMO for a knock-on in the build-up.
"It was not pretty," said Borthwick, whose side are likely to face another Pacific Islands team, Fiji, in the quarter-finals.
"It was not the performance we wanted but you saw a determined group of players finding a way to navigate being behind on the scoreboard and then finding a way to get the result at the end," Borthwick added.
