Tasked with leading the line Rashford, partner-in-crime Jamie Vardy was almost in for a second but was well thwarted by Navas.
However, the Three Lions could not add any more goals to their tally for the first stanza and took a 1-0 lead into the break.
South Korea were held to an unimpressive 0-0 draw against Bolivia while Iceland, the surprise packages of Euro 2016 who are looking to pull off more upsets in Russian Federation, drew 2-2 at home to Ghana after leading 2-0.
Ronaldo, who hadn't played since leading Real Madrid to a third straight Champions League title last month, set up one of Portugal's goals at the Stadium of Light. Jamie Vardy and Welbeck have proven their worth, but Rashford gave the most compelling case during the friendlies to join Kane.
"A little bit different in that obviously (there was) a slightly different profile of players, so maybe we didn't get as many men in the box at times".
Argentina cancels match with Israel amid protests
Alon Liel, a former director-general of Israel's Foreign Ministry, saw the dustup as fallout from the embassy move. It is unclear whether Argentina will play another warm-up, or arrive in Moscow ahead of schedule.
'You work on them [goals] in training every day and when one comes up in a game it's a reward, ' said Rashford.
"It wasn't "first-team played Nigeria and second-team played today". Rashford has given Southgate a massive selection dilemma ahead of the first group game against Tunisia. Rashford caught the eye from the off with a sublime piece of skill down the left that forced a corner from which his United team-mate Phil Jones saw a looping header turned onto the bar by Keylor Navas. Rashford only scored seven for runners-up Manchester United, so when you look it at like that, it's a no-brainer; Sterling has to start which is why he's 1/20 to get the nod.
Southgate could also be looking for stability in midfield and Henderson will be a prime contender for a place alongside Eric Dier.
It would be a big risk to play Rashford.
As for the game itself, England put in a decent performance. Gareth Southgate's a sensible guy.
"Towards the end of the season you can see that he cares so much that he's trying too hard", said Southgate post-match.
"They (the team) are going to make errors but, by taking risks, they show the glimpses of quality like Marcus' opening goal. His performance wasn't ideal but he was enjoying his football and that was good to see".