South African Louis Oosthuizen is one stroke off of Rory McIlroy's lead through 15 holes on the second day of the 2012 Deutschebank Championship held at TPC Boston.

McIlroy took the lead in the event earlier today from Seung-Yul Noh, after shooting 6-under par on the day to improve to 12-under on the weekend.

Oosthuizen has been very impressive thus far on the day, shooting five birdies, an eagle and a bogey to jump from eighth to second overall.

Also having an impressive Saturday are Charl Schwartzel and D.A. Points, both of whom also shot 6-under through 18 holes.

They, along with Seung-Yul Noh, Tiger Woods, Chris Kirk and Jason Dufner, are tied for fourth. Of that group, Woods still has golf left to play this afternoon, as he is through 15. A good finish to his Saturday could put Woods in the top three overall.

For a full leaderboard, visit Golf.com.