Jennifer Lopez's first triathlon goes swimmingly

Jennifer Lopez survived her first triathlon!

Lopez finished the Nautica Malibu Triathlon on Sunday -- we're talking a half-mile swim, 18-mile bike ride and 4-mile run -- in 2 hours, 23 minutes and 28 seconds.

Way to go, J-Lo!

Proud hubby Marc Anthony escorted her to a VIP area where she ran into her "Wedding Planner" costar Matthew McConaughey, who did the race in 1 hour, 43 minutes and 48 seconds.

Lopez had her trainer Gunnar Peterson along for the ride, just to give encouragement. Ah, we knew she could do it.

Photo: WireImage