Bayern Munich 2-1 Sevilla (aet): Martinez the unlikely Super Cup hero against obdurate opponents
Hansi Flick's treble-winning outfit struggled against a stubborn Sevilla side who had been unbeaten since February – a run that included a record sixth triumph in the Europa League, formerly the UEFA Cup – and the LaLiga side went ahead through Lucas Ocampos' penalty.
Leon Goretzka levelled before half-time but Bayern's run of 22 successive victories would have come to an end had Youssef En-Nesyri not been thwarted by Manuel Neuer in the dying stages of normal time.
But it was fellow substitute Martinez, linked with a return to Athletic Bilbao after eight years in Bavaria, who scored his first goal since April 2019 to earn Bayern yet more silverware.
Bayern opened their 2020-21 season with an 8-0 rout of Schalke but it was Sevilla who struck first through Ocampos' penalty.
Luuk de Jong's cushioned header reached Ivan Rakitic, and the midfielder – back at the club after re-joining from Barcelona – was barged over by David Alaba, with Ocampos outfoxing Neuer from a no-look spot-kick.
Robert Lewandowski failed to beat Yassine Bounou from a one-on-one as Bayern responded, but he made up for that before half-time, laying the ball back for Goretzka to pick his spot and score the equaliser.
The Champions League winners thought they had the lead within six minutes of the restart after Muller teed up Lewandowski, having initially been presented with the chance himself by the Pole, but VAR spotted Bayern's number nine was offside when first collecting Leroy Sane's pass.
It was one-way traffic thereafter as Bounou denied Serge Gnabry and Diego Carlos blocked the rebound from Sane, who had a goal disallowed himself after Lewandowski was adjudged to have fouled Sergio Escudero in the build-up.
But it was Sevilla who should have won the game in normal time when Jesus Navas released En-Nesyri on a counter-attack, only for Neuer to make the save from an attempt that was too easy to anticipate.
Sevilla had renewed optimism at the start of the additional period, though En-Nesyri looked offside when he aimed an effort at goal that Neuer's right foot diverted onto a post.
And Martinez made him pay five minutes after coming on when he directed a header past Bounou after the goalkeeper could only push Alaba's effort back in front of him.