9:33 AM PT -- Serena was defeated by Angelique Kerber, 6-3 6-3, who won her first career Wimbledon title and third major. Serena was interviewed after the match, saying she was disappointed she couldn't get the win for all the moms out there ... but thanked everyone for their support and said she was happy to be back.

Meghan Markle has friends in high places, and not just at the Palace ... because she showed up to watch her good friend Serena Williams try to make some history.

Meghan brought sister-in-law Kate Middleton along for the ride to sit in the peanut gallery at Wimbledon, to watch Serena attempt a super-human feat ... bouncing back after a difficult post-pregnancy to tie the record for Grand Slam wins.