VIDEO: How Belgium fought back from two goals to defeat Japan
Belgium showed their fighting qualities as Nacer Chadli's 94th-minute strike completed a thrilling 3-2 comeback victory over Japan in their World Cup last-16 clash in Rostov
Martinez's side were overwhelming favourites to progress to the quarter-finals after pipping England as winners of Group G but two goals in four minutes from Genki Haraguchi (48) and Takashi Inui (52) gave Japan a shock 2-0 lead.
Jan Vertonghen's looping header (69) gave Belgium hope before substitute Marouane Fellaini's trademark finish (74) from Eden Hazard's cross brought the scores level.
With the last kick of the game, a sweeping counter-attack was finished off with Chadli at the far post as Belgium progress to face Brazil in the last eight on Friday at the Kazan Arena.
The Belgians booked a third successive quarter-final spot at a major tournament despite a resolute performance from Japan, whose quest to reach the last eight of a World Cup continues after seeing their valiant efforts come to nothing.
Akira Nishino's men crawled into the last 16 via a superior fair-play record to Senegal, and Shinji Kagawa fired a warning sign inside a minute after dragging a left-foot shot a yard wide.
Yuya Osako almost embarrassed Thibaut Courtois when his loose touch initially squirmed through the legs of the Chelsea 'keeper before he pounced on the ball before it crossed the line, but it was only until the second period that the game sparked into life.
Gaku Shibasaki's sliding pass beyond Vertonghen was swept into the bottom corner by Haraguchi and, after Dries Mertens' cutback was volleyed against the post by Hazard, a thunderbolt from Inui left Belgium staring down the barrel of defeat.
Sublime control from Kagawa set up the Real Betis-bound midfielder, and he had time and space to pick his spot as he curled a right-footed shot low to the right of Courtois' desperate dive.
But after Romelu Lukaku headed wide from five yards out, Belgium handed a lifeline as Inui's failed clearance landed on the head of Vertonghen, and the Tottenham defender's looped header back into the box fortuitously found the far corner.
Fellaini's close-range header from Hazard's cross five minutes later restored parity before Eiji Kawashima did well to tip over another aerial attempt from Lukaku, but just as the game appeared to be drifting towards extra time, Belgium broke Japanese hearts in devastating fashion.
Within 10 seconds of defending a corner, Kevin De Bruyne broke at pace to combine with Thomas Meunier down the right and after Lukaku dummied the wing-back's cross, substitute Chadli made no mistake in stroking the ball under Kawashima.