Hired in June 2009 as the Williams College Men's Tennis Head Coach, Dan Greenberg '08 has led his team to three NCAA Final Fours — finishing fourth in 2011, third in 2012 and winning the NCAA Championship in 2013.

The 2013 Eph team also won the NESCAC Championship, the first in 10 years, earning Greenberg NESCAC Co-Coach of the Year. Additionally, CaptainU, the youth and college sports network, named Greenberg the 2013 National NCAA Division III Men's Tennis Coach of the Year. Prior to 2013, the last time the Ephs won the NCAA Championship was in 2002.

Since Greenberg's first year at the helm in 2009-10, the Ephs have reached the NCAA Quarterfinals or better seven times. Fourteen Ephs have earned All-American honors (9 were multiple-time All-Americans). His top doubles teams have won three ITA National Titles (2011, 2012, 2021), and his 2017 doubles team of Brian Grodecki and Alex Taylor took second place at NCAAs. In 2023, Matt Kandel '25 took second place in the NCAA Singles Championship. 

In January 2020, Greenberg spent the month coaching ATP players Nicholas Monroe and Jackson Withrow at the Australian Open, Bendigo Challenger and NY Open. He returned to the 2023 Australian Open with Jackson Withrow and Nate Lammons, beginning a year in which they both rose to top-30 ATP rankings.

Prior to coaching at Williams, Greenberg spent one year at the University of North Carolina, working under head coach Sam Paul —5-time ACC Coach of the Year — and Coach Tripp Phillips — 2006 U.S. Open Doubles Semifinalist. He was primarily involved with individual development, film analysis and on-court coaching for the Tar Heels.

At Williams, Greenberg was a three-time All-American, 2008 NESCAC Player of the Year and ITA Northeast Player of the Year, and 2005 NESCAC Rookie of the Year. He also served as a Junior Adviser, working with first years to ease their transition into college life. He studied English Literature and Creative Writing and now holds a master's in education from Massachusetts College of Liberal Arts.

All-Americans Since Greenberg's Arrival:
Nick Lebedoff (Singles)
Felix Sun (Singles)
Trey Meyer (Singles and Doubles)
Bryan Chow (Doubles)
Matt Micheli (Doubles)
Alex Schidlovsky (Doubles)
Alex Taylor (Doubles)
Brian Grodecki (Singles and Doubles)
Peter Frelinghuysen (Doubles)
Matt Kandel (Singles and Doubles)
Chase Cohen (Singles and Doubles)
Nicholas Chen (Singles and Doubles)
Jason Shuler (Doubles)
Shawn Berdia (Doubles)