One of six first-timers playing in the season-ending championship, the Colombian finished the front side at 1-under-par 35, then stormed the first half of the back nine to earn a spot at the top of the leaderboard.
Park moved into contention after making the turn at 3-under-par 33. Like Baena, Park found herself in trouble on the 389-yard par-4 first hole, where she made bogey. But unlike her Columbian counterpart, Park was able to make a steady recovery with par'birdie on the next two holes.
Park led outright at 4-under, but bogeyed her final hole.
Baenas performance is nothing less than notable. In her first appearance in the event, played this year at Trump International Golf Club at West Palm Beach, Fla., she has given early indications that she can hold her weight against the Tour's toughest competitors.
The 24-year-old finished in the top 10 three times this season, recording a career-best finish at the Kathy Ireland Championship ' where she finished in third place. Baena matched her career low at the Mizuno Classic with a tie for third, which moved her to 33rd on the money list.
Baena is among a select group of young players who have dramatically improved their position on the money list from last season. After finishing 101st in 2000 with $77,144 in prize money, Baena moved to 33rd this season - earning a career-best of $306,819.
She received a spot in the elite field, in which the top 30 players on the money list qualify, when three players withdrew.