OK it really took 11 seconds. But it sounds cooler to say “Mission 10 in 10 seconds” This mission introduces the red tank, which rapid-fires ordinary shells (i.e. rebound once).
As the mission begins, I generally move to the lower center of the battlefield, firing two shells up the center-left corridor on the way. These two shots will sometimes take out the tank that started out at the top center of the battlefield, but which almost invariably move to the corridor as the mission begins, running into those two shots.
With just two red tanks and many high-rising barricades, the general tactic in this mission is to stay in the lower center where you can see things clearly, and duel with these tanks at short distance (see General Strategy against Red Tanks). If the above tactic did not take out the first red tank, you would bascically do the following twice: stick to the lower-center barricade near either end where the red tank is anticipated to emerge, paying attention to the enemy fire that will be rebounding (from the bottom) literally left and right. Then, as soon as the red tank emerges, move up close and begin your duel! As explained in the General Strategy against Red Tanks, this actually carries little risk
Next: Mission 11.