Even the centre-back's close-range finish in the first half was relatively routine but neither he, his team-mates or manager will mind as it secured a third successive league win and back-to-back home wins in the top flight time for the first time in almost a year.
Jagielka's fifth goal of the campaign for the Toffees - he also scored in England's win over San Marino in October - represents his best goalscoring return in eight seasons at Goodison Park, with the strike at Goodison Park securing a 1-0 win.
His side were certainly grateful for it as they recorded only their second win over top-half opposition this season.
If they were going to do it against anyone, however, then Southampton were the team as they have not won in 10 visits, of which they have lost eight, with their last success coming in November 1997
Considering they had the chance to reclaim fifth place after Liverpool's earlier defeat at Arsenal, Saints were strangely lacklustre after dominating the opening 15 minutes.
Ronald Koeman's side were described by Everton counterpart Roberto Martinez as the "revelation team" of the season but they never came close to living up to that billing.
With his midfield options reduced by the news Darron Gibson had broken a metatarsal and is likely to miss the remainder of the season, Martinez made a slight tweak with James McCarthy pushed forward into a quartet behind lone striker Arouna Kone with Gareth Barry the sole holding player.
It made a difference in that it put additional pressure on Southampton further up the field and McCarthy's energy ensured their opponents were less comfortable on the ball.
But it took a while for that to take effect and Everton could easily have been behind as Shane Long's hanging cross was met with a looping volley from Graziano Pelle which Tim Howard had to claw out from under the crossbar.
McCarthy was criticised for his lack of passion and enthusiasm in the Republic of Ireland's recent internationals but he seemed to enjoy being given a bit more freedom and only Ryan Bertrand's last-ditch intervention denied him a goal after being played in by Kone.
Without leading scorer Romelu Lukaku, still not fully recovered from a hamstring injury, Everton needed someone else to shoulder the responsibility but not many would have backed Jagielka to be their greatest threat in the first half.
However, the England defender reacted sharpest to sweep home Barry's cross from close-range at a 16th-minute corner and later header over another Leighton Baines set-piece when Nathaniel Clyne had deflected behind Leon Osman's header.
But the hosts did not have it all their own way, with James Ward-Prowse unlucky not to find the net on two occasions having left Howard rooted to the spot with a free-kick which whistled just wide and then seeing the United States international throw up a hand while diving the wrong way to deny his long-range drive.
The second half was even less of a spectacle, having all the feeling of an end-of-season affair five weeks early, with neither goalkeeper remotely troubled.
That will have been of much greater concern to Koeman than it was to Martinez, who nevertheless was booed for replacing Barkley with Muhamed Besic after 71 minutes.
The Spaniard will argue the ends justified the means but while he still talks about reaching 40 points - they are three points short in 11th place now - fans will continue to voice their complaints about a lack of ambition.
Source : PA
Source: PA