Billionaire Phil Knight, cofounder of Nike Inc., pledged $500 million to Oregon Health & Science University’s cancer institute in 2013. The gift came with one catch. The academic health center would have to raise an equivalent amount within two years.

They just did it.

“Phil is a competitor and likes to set audacious goals,” Brian Druker, director of the OHSU Knight Cancer Institute, said in a phone interview. “When we started 22 months ago, it looked like an improbable task.”

The $500 million donation by Knight and his wife Penny is the largest single gift ever made to a U.S. college, while the $1 billion total is the biggest successful matching pledge on record, according to Indiana University’s Lilly Family School of Philanthropy. The money will be used to support research into the early detection of cancer.

The billionaire and his wife Penny have now given $725 million in total to OHSU, according to data compiled by Bloomberg. That includes the $125 million they gave to OHSU’s cardiovascular unit in 2012 and a $100 million gift in 2008, which saw the cancer institute named after them.

On the matching side, the state of Oregon raised $200 million for construction of two buildings. The largest gift from an individual, aside from Knight, was $100 million from Gert Boyle, chairman of Columbia Sportswear Co.

Knight, 77, is the 31st-richest person in the world with $24 billion, according to the Bloomberg Billionaires Index. He founded the sportswear maker in 1964 with Bill Bowerman, his former track coach at the University of Oregon.

Earlier this month hedge-fund manager John Paulson gave $400 million to Harvard University’s engineering school, the biggest donation in the college’s history while Stephen Schwarzman, founder of private-equity firm Blackstone Group LP, gave $150 million to Yale University for a student center in May.