Who won the US Open men's tennis title in 1990 at the age of 19?

Petros Sampras (born August 12, 1971) is a retired American tennis player widely regarded as one of the greatest in the history of the sport. He was a right-handed player with a one-handed backhand and a powerful, precise serve that earned him the nickname "Pistol Pete". His professional career began in 1988 and ended at the 2002 US Open, which he won, defeating rival Andre Agassi in the final. He was inducted into the Hall of Fame in 2007.

Sampras finished 1990 at World No. 5, having started the year ranked World No. 61 just prior to the start of the Australian Open.  His first professional singles title came in February at the Ebel U.S. Pro Indoor in Philadelphia, where he defeated sixth-ranked Andre Agassi, eighth-ranked Mayotte, and eighteenth-ranked Andrés Gómez in the final. This title elevated his ranking into the top 20 for the first time.

In September of 1990, Sampras captured his first Grand Slam title, at the US Open. Along the way, he defeated sixth-ranked Thomas Muster in the fourth round and third-ranked Ivan Lendl in a five-set quarterfinal, breaking Lendl's streak of eight consecutive US Open finals. He then defeated 20th-ranked McEnroe in a four-set semifinal to set up a final with fourth-ranked Agassi. Sampras beat Agassi in straight sets to become the US Open's youngest-ever male singles champion at the age of 19 years and 28 days. He played five more tournaments and won the Grand Slam Cup to complete his year.