ATHENS, Ga. -- Southern California followed a record-setting second round with a tough-as-nails third round as the Trojans, led by individual leader Annie Park, grinded through to extend their lead to 17 strokes with 18 holes to go at the 2013 NCAA Women's Golf Championships at the University of Georgia G.C. on Thursday.

The Trojans, playing in the final threesome of the afternoon wave, combined for a 3-under 285 and now stand at 19-under 845 (284-276-285), which is 17 better than second-place Duke (862). The Blue Devils turned in the third-best round of the day (behind only USC and Auburn), but couldn't make up any ground. Alabama, 12 back in second place after the second round, dropped to a tie for third at 9-over 873 with Purdue and UCLA.

USC is after its third team title in program history after victories in 2003 and 2008. The Trojans entered the NCAAs this year having won five of their past six events and are a round away from securing lucky No. 7.

The Trojans began the day with a 12-stroke lead against Alabama and 15 better than Duke. Near the halfway point of the day, the Trojans were a combined 5-over and Duke had climbed into second.

"There were some keys things that happened on the back side. We were 5-over for quite a while and came back all the way to 3-under," USC head coach Andrea Gaston said. "On the front 9, which was our back 9 yesterday, we didn't do as well. We had to do some battling and with the wind, it made it more difficult. And the pin placements were tough.

"We turned at 5-over and certainly that had me concerned ... But the team kept at it and got some momentum with some birdies in the front of the lineup, Sophia made some good saves and Annie finished really strong. This is a testament to how hard our girls have worked, not to give up and that a birdie can really turn things around."

Park will begin the final round with a two-stroke lead after finishing the day at 9-under 207 (70-67-70), two better than Alabama's Stephanie Meadow and Mississippi State's Ally McDonald.

Park opened with a bogey, but she got back to par on 6. She went to 2-over with bogeys on 12 and 13 before finishing strong with birdies on 13, 14, 17 and 18.

Her 9-under after 54 holes tied the NCAA record, matching three other players including USC's first NCAA individual title winner, Jennifer Rosales in 1998. Park is now close to becoming the Trojans' fourth.

"I was struggling on the front, but glad I got it back together on the back 9," Park said. "It's awesome how the team is playing. Hopefully we do the same tomorrow and play each shot one at a time."

Sophomore Doris Chen, 3-over through 9, birdied 10, saved par on 11 with a clutch putt and finished with birdies on 15 and 16 to get back to even. She is now tied for 45th at 6-over 222 (72-78-72).

"[Wednesday] I really messed up my round and [Thursday] I was coming in determined to improve," Chen said. "I'm still trying to get used to a new putter and having some distance control issues, which cost me a bit. On the back 9 I was trying to hit it as close to the pin as I could and give myself a good chance to get some birdies and I did."

Junior Sophia Popov was 3-over through nine, but was 1-under on the back and could easily have been 4-under on the back, but missed three consecutive birdie putts by inches on her final three holes. She is tied for 11th at 1-under 215 (71-70-74).

Freshman Kyung Kim was the lone Trojan under par on the front 9 at 1-under, but was at par after 14 before finishing with birdies on 14, 15 and 17. She is now fourth overall at 4-under 212 (74-69-69).

"[Thursday], I was hitting the ball really well, but because of the wind my distance control was a little off and that cost me a couple bogeys. But everything came together towards the end," Kim said. "And the team is doing great. Everyone on the team grinded out and played strong."

Junior Rachel Morris tied for 25th at 3-over 219 (71-70-78) after her first tough round of the event.

"I know what [losing by one stroke at NCAAs] feels like [after last year] and it doesn't feel good," Popov said. "We are fighting for every shot no matter what the score is and having fun. We need to try to stay aggressive and not play scared."