In a small bowl, combine the brown sugar, smoked paprika, garlic powder, onion powder, salt, and black pepper to make the spice rub.
Pat the brisket dry with paper towels and rub the spice mixture evenly over the entire surface, pressing into the meat.
Set Instant Pot to 'Sauté' on high. Add olive oil and sear brisket fat-side down for 4-5 minutes per side until a deep brown crust forms. Remove brisket and set aside.
Deglaze the pot with a splash of beef broth, scraping up browned bits. Turn off 'Sauté'.
Place the trivet in the Instant Pot. Pour in remaining beef broth, Worcestershire sauce, and liquid smoke. Place seared brisket on trivet, fat-side up.
Secure lid, set steam release to 'Sealing', select 'Pressure Cook' or 'Manual', and cook on high for 90 minutes.
Allow pressure to release naturally for 20 minutes, then carefully switch valve to 'Venting' to release remaining steam.
Remove brisket and rest 10-15 minutes before slicing against the grain.
Serve slices with some of the cooking liquid (jus) spooned over the top.
Notes
Slicing against the grain ensures maximum tenderness. Leftover cooking liquid can be thickened with a cornstarch slurry (1 tbsp cornstarch + 2 tbsp cold water) for a delicious sauce. Great for next-day sandwiches—reheat slices in the jus.