If you cannot match up with your opponent with speed or spin, then you need other weapons. One of the best ways to beat faster and more powerful players ("bashers") is with ball control. Just as an all-out attacker uses his serve and receive to set up his attack, a ball control player uses serve and receive to take control of the rally. For him, it's all about ball control, placement, and shot selection. If he's able to use his ball control to make the basher uncomfortable, he's won the battle. So how do you do this?
Start with receive, for it is while serving that bashers dominate, given the chance. But is he really dominating on his own, or are you letting him dominate? For example, if the basher has a strong forehand, and follows his serve with his forehand over and over, what are you doing to stop this? Few players can really dominate the whole table with the forehand against well-placed shots. Does the basher really do so, or is the receiver keeping the ball well inside the corners, so the basher doesn't have to cover the whole table? Ball control means ball control; the ball control player needs to be able to return the serve anywhere on the table. This means mostly one of two things: either pinning the basher down by relentlessly returning the ball to the extreme wide backhand (even outside the corner if returning crosscourt), or by aiming it there, and last-second returning it to the extreme wide forehand (again, even outside the corner for crosscourt shots). If you can't do this, then you don't have the ball control (yet) to play a ball control game. How can you learn to do so? By practicing it in game after game until you get it down.
Now supposed your opponent attacks off his serve from both wings, so wide-angled returns to the backhand aren't really effective. Now the basher is ready to bash from both wings - or is he? Try quick returns to his elbow (or a little to his backhand if he favors the forehand from the middle), and watch his shots begin to crumble as he makes last-second decisions. Plus, by going to the middle, it draws the basher out of position, giving you an opening to the corners on the next shot.
Now we move on to serving. The basher serves so he can attack, usually trying to end the point as quickly as possible. The ball control player should also mostly serve so he can attack, but in his case he's not trying to end the point quickly. He's looking to attack to make the basher uncomfortable, because the basher isn't comfortable when he's not attacking. So attack first, and force him to either defend or go for difficult counter-attacks. The key again is placement. Go to the side that gives the attacker the most trouble. If he can't block or counterloop consistently on the forehand, then nail him there over and over. Even if he does make the return - even a strong one - it opens him up on the backhand side. Or attack his middle (roughly his elbow), which should be your default opening attack anyway. Or if he's weak on the backhand defense (usually blocking), then go there. Or drive him crazy by going everywhere. Just do each shot with a purpose - to make the basher uncomfortable, and to take him out of position for the next shot.
Once in the rally, the ball control player has a 2-1 advantage over the basher. He wins most of the points when he has the initiative, as does the attacker. But when neither has the initiative, guess who has the advantage? The ball control player, who has successfully taken away the basher's attack, thereby bringing him down a level.