Then, on 32 minutes, another good chance from a corner went begging, when Ruben Loftus-Cheek, in plenty of space having evaded his marker, headed wide at the far-post.
Panama held a 1-0 lead at halftime because of an own-goal in which Jose Luis Rodriguez's hard shot deflected off of defender Yassine Meriah in the 33rd minute.
With the victory, Belgium gets what appears to be an easier match in the next round against Japan on Monday in Rostov-on-Don. Both teams are guaranteed a place in the next stage of the championship.
Whoever comes second would also play two of the three knockout rounds to the final in the comfort of Moscow - where Belgium have their camp - whereas the victor faces thousands of air miles travelling to Rostov-on-Don, Kazan and St Petersburg.
While Group H winners Colombia are seen as tricky opponents, Southgate said he had had no preference about who his team would line up against in the last 16.
Martinez made nine changes, with Romelu Lukaku, Eden Hazard and Kevin De Bruyne among those left out.
Speaking in his prematch news conference on Wednesday, Martinez said the results from the scans had been positive for the long term, but he fears Belgium's all-time top goal scorer might have to sit out the England encounter.
Mort de Claude Lanzmann : les chaînes bouleversent leurs programmes
Le décès du cinéaste a été confirmé par l'attachée de presse de son dernier film, Les quatre soeurs , sorti en salles ce mercredi. Réalisateur de Pourquoi Israël , Tsahal , Napalm ou encore Un vivant qui passe , il est une référence en matière d'investigation.
It was Belgium who began the more brightly, quickly establishing their passing game and controlling possession.
England´s forward Harry Kane celebrates with England´s midfielder Jordan Henderson (R) after scoring a penalty during the Russian Federation 2018 World Cup Group G football match between England and Panama at the Nizhny Novgorod Stadium in Nizhny Novgorod on June 24, 2018.
Colombia, which played in the quarterfinals four years ago in Brazil, finished atop its group and is the fourth South American team to advance.
Poland has already been eliminated from advancing but Japan can move on to the round of 16 with a draw, and even a loss with help from other teams.
In the match which will decide who finishes top in Group G, Southgate dismissed suggestions that there would be any circumstances in which England would not play to win despite opting to rest so many key figures.
The 41-year-old was the first referee to brandish a red card in this World Cup as he dismissed Colombia's Carlos Sanchez for deliberate handball and gave Japan a penalty in their 2-1 success.
Gareth Southgate seemingly opted for the latter, making eight changes to the side that thrashed Panama 6-1.
But will England's World Cup campaign now suffer now they've deliberately ended their winning momentum?
Ignoring, if it's possible, the debate about the wisdom of cherry-picking the route through the knockouts by teams who have not reached a semi-final between them since 1990, this was a match worth winning.