Gabrielle Union kept it sexy on the beach this Memorial Day Holiday weekend with her sister-in-basketball Savannah Brinson.  The two ladies were spotted soaking up the sun in their bikinis before cheering on their men at last night's Heat vs. Celtics playoff game.

Check the pics inside...

The seemingly flawless 39-year-old actress Gabby Union threw on her straw hat and teeny bikini to hit Miami Beach yesterday in all her tight and toned glory.  She often tweets about her hard core workouts. And clearly they're paying off.

She and LeBron James' fiancee, Savannah, and another friend were spotted hitting the ocean and the sand on Memorial Day or some girly relaxation time.

Savannah's also been tweeting about her pre-wedding workouts as she donned a cute straw hat from Aldo.

Fun!

Gabby, who is filming her new BET show "Being Mary Jane" with writer Mara Brock Akil, is a spokesperson for Neutrogena's skin disease awareness campaign.  She recently said about why people should pay attention to discolorations and moles:

'I don’t tan on purpose, but I do a lot of beach workouts. But I go SPF 110.

'As an African-American woman, culturally we have been told that we have natural protection against the sun, but we’re absolutely part of the one in five.

As I’ve gotten older, I’ve seen relatives’ moles change shape, and they think, "That’s cute — it’s like Janet Jackson!"

'But it’s not cute — it’s called melanoma.'

She's looking fantastic these days.

Then the Think Like a Man actress was spotted playing supportive girlfriend to Dwyane Wade later yesterday at Game 1 of the NBA Eastern Conference Finals at American Airlines Arena.  Heat won 93-79.

Pics via Bauer Griffin/Splash