He was also there for Nadal's finals victory against South Africa's Keven Anderson. Woods sat in Nadal's players box along with his coaches, friends and family.
This isn't the first time Woods has shown off his silver and black fandom. He posted a photo of his pool table in July. The table is outfitted with silver and black cloth and has an large Oakland Raiders logo in the center.
The 14-time major champion attended the matches with his children, including son Charlie and daughter Sam. Bill Gates, Leonardo DiCaprio, Robert Redford, Julianna Margulies, Live Schreiber, Jerry Seinfeld, Justin Timberlake, Jessica Biel, Tony Bennett and Candice Bergen also enjoyed the tournament as spectators.
Nadal won the final match 6-3, 6-3, 6-4 to push his number of Grand Slam singles titles to 16 overall.
Woods, 41, hasn't played competitive golf since January. He is coming off of his fourth back surgery. In August, Woods took to the course to showoff his pitching skills.
"Dr. gave me the ok to start pitching," Woods wrote on Twitter.
Woods is currently ranked No. 1,137 in the world and hasn't won a major since the 2008 U.S. Open at Torrey Pines.