Monday evening was hard fought but worth it in the end.
England were a delight in the opening half hour, a mixed bag in the middle third and then toiled in the latter. Mercifully for Gareth Southgate, the Head of Harry answered a nation's call.
That victory over Tunisia was by no means perfect but it did put down something of a marker. No one in this World Cup has roared out of the blocks quite like England did in Volgograd; that they weren't four to the good by the time of Ferjani Sassi's equaliser was down to carelessness rather than a lack of creativity.
If the men from North Africa could not cope with England's pace and movement in the opening stages it is tough to see how an ageing Panama side might fare any better.
Los Canaleros were insipid during their opening game, a 3-0 loss to Belgium, but their arrival at their first World Cup was won on merit: by qualifying, they trumped the land of Trump.
Now they find themselves on the verge of an exit with six days of kicking their first ball in a finals. Only a win is likely to scotch that eventuality. England, meanwhile, will be hoping for a smooth passage to the Round of 16.
Here are five things to watch out for on Sunday.