The ongoing battle between Apple and Samsung rages on today. This time, however, Apple has dealt a significant blow: U.S. District Judge Lucy Koh granted a preliminary injunction to stop sales of the Samsung Galaxy Tab 10.1 in the United States.

Apple's claim against Samsung's former flagship tablet is that its design too closely resembles the iPad.

"Although Samsung has a right to compete, it does not have a right to compete unfairly by flooding the market with infringing products," wrote Koh in her decision. Apparently, the court decided that the Galaxy Tab 10.1 is "virtually indistinguishable" from the iPad's design and therefore infringes on Apple's intellectual property.

Furthermore, said Koh, since Apple and Samsung are direct competitors in the tablet space and "design mattered more to customers in making tablet purchases," Apple would be harmed by future 10.1 sales.

"The relief being given to Apple here is extraordinary,” said Colleen Chien, a professor at Santa Clara Law in Silicon Valley. “Preliminary injunctions are rarely asked for and rarely granted."

The injunction will go into effect as soon as Apple posts a $2.6-million bond to protect Samsung from losses in case it is later determined that that injunction shouldn't have been granted in the first place – which may happen, as Samsung filed an appeal a mere five hours after Judge Koh's order.

Either way, this isn't the end of the global Samsung versus Apple legal battle.

It's interesting that Apple would be so aggressive toward Samsung in the tablet space, considering the fact that while the iPad sold 13.6 million units from January to March this year, Samsung only sold 1.6 million tablets in total from its broad range of devices.

Samsung may have much more to worry about in the smartphone market, anyway, as some estimates suggest the Korean manufacturer has lost two million unit sales of the Samsung Galaxy S III this month due to rampant demand causing global shortages of the device.