The sentence in which a word is INCORRECTLY spelled is:

"His breathe smelled of garlic."

The correct spelling should be "breath" instead of "breathe."

Here's an explanation for each sentence:

1. "He hoped that he had won the prestigious award." - All the words in this sentence are spelled correctly.

2. "I could never be as talented as him." - All the words in this sentence are spelled correctly.

3. "His breathe smelled of garlic." - The word "breathe" is misspelled as "breathe." The correct spelling should be "breath," which refers to the air taken into or expelled from the lungs.

4. "A woman gasped in horror at the sight of him." - All the words in this sentence are spelled correctly.

Therefore, the sentence "His breathe smelled of garlic." contains an incorrectly spelled word.