Rashford played in Dele Alli and his low cross found fellow substitute Welbeck at the far post.
Marcus first came on to the scene doing just that having scored in several of his debuts and there's hope he can be talismanic for Gareth Southgate's side.
Rashford could persuade the Portuguese boss to keep hold of him and give him a selection headache if he maintains his fine form during the World Cup.
Twenty-five yards out with minimum backlift and leaving a three-time Champions League winning goalkeeper for dead - Marcus Rashford's stunning strike against Costa Rica would, had it been saved for 11 days' time in Volgograd, gone down in the pantheon of great England goals.
Jordan Henderson, captaining the side in Kane's absence, saw a powerful effort turned behind by Navas. Sterling and Kane are unlikely to be dislodged from Southgate's first-choice team any time soon, and as such chances for Rashford may initially have to come from the bench. They played the game in the Costa Rica half and asserted themselves, with good tempo, as well as width and pace to get behind their opponents.
Recent friendly games show a mixed bag of results for the Central Americans although the 3-0 home win over Northern Ireland and 1-0 victory away to Scotland could suggest they do well against British sides. England had 73% possession but created very little.
Butland will start, but should Pickford be number 1 for England?
The second half was a more subdued affair in terms of chances, the ten substitutions perhaps affecting the game's flow.
England rounded off the night comfortably, though. He was always trying to find space between the lines and dribble past defenders.
The temptation of the heavy plus money with Costa Rica is tempting considering it only takes one bounce for the ball to end up in the back of the net and it may only take one goal to win this match.
However, it's safe to say that this team hasn't been properly tested.
England take on Tunisia in their opening group game and Southgate insisted before the match that places in his starting line-up were still up for grabs.