Meghan Markle Flew Commercial to See Friend Serena Williams Play in U.S. Open

The duchess has received criticism for flying on private jets.

Meghan Markle is in New York City on best friend duty!

The Duchess of Sussex flew to the Big Apple to see her pal Serena Williams play at the U.S. Open on Saturday. The last-minute trip came after Williams won Thursday night's match, putting her in the finals.

Williams is eyeing her 24th Grand Slam title. If she clenches it, she'll tie the record for most wins with Margaret Smith Court.

Meghan is said to have left London at 8:30 a.m., flying commercial amid backlash over recent private jet trips with her husband, Prince Harry. 

Critics say the gas-guzzling trips literally fly in the face of their support of environmental causes. But the royal couple say they've purchased carbon offsets in effort to balance out their impact on the environment. 

"I spend 99% of my life traveling the world by commercial," Harry said at a travel industry conference in Amsterdam Monday. "Occasionally, there needs to be an opportunity based on a unique circumstance to ensure my family are safe and it’s genuinely as simple as that."

Meghan was last in Manhattan in February for her baby shower, which was thrown by Williams.