After a goalless first half, Japan struck twice in seven minutes following the interval to take full control of a gripping last-16 tie in Rostov-on-Don on Tuesday morning (AEST).
"No negatives today, it was about getting through", Martinez said.
"That's what happens in the World Cup".
Belgium scored a last-gasp victor to beat Japan on Monday and set up a World Cup quarter-final against Brazil.
Belgium responded but Hazard's shot rattled the post and Japan doubled its tally in the 52nd when Inui picked up the ball 25 metres out and fired a missile into the back of the net.
Desperate for a goal to get them back in the game, Lukaku headed wide with an hour approaching.
Lakers Trade For Kawhi Could Clinch LeBron Signing
Spurs teammates questioned the severity of the injury as Leonard's absence continued after the team had cleared him medically. However, Leonard will only reportedly sign a long-term deal with a Los Angeles team, either the Lakers or Clippers.
With centre back Vincent Kompany back in the line-up for the first time since picking a groin strain in a warm-up game, Belgium had looked safe at the back but uninspired up front.
Lukaku, who was marked, left it for Chadli to tap home and cap Belgium's stunning win right before the final whistle.
This was Belgium's first goal on its comeback.
It was the whole Belgium team who were facing humiliation seven minutes into the second half as Japan opened up a surprising lead through two high-quality goals.
At the other end, Courtois saved Keisuke Honda's wickedly curling free shot which led to the winning goal.
- Priyanka Chopra Said the Cutest Thing About Nick Jonas
- Best Twitter reactions after South Korea knock Germany out
- Ronaldo follows Messi out of Russian Federation as Portugal hit Uruguay roadblock
- Samsung has finally agreed to pay up for copying the iPhone
- A Strawberry Moon will sweeten up the night sky tonight
- Merkel secures asylum seeker return deals with 14 EU countries
- A final good-bye: Toys R Us closes its doors forever
- Sanju BEATS PK to become director Rajkumar Hirani's biggest opener
- Mascherano calls time on career after painful France defeat
- Sampaoli sure Argentina can find feet against France