Mat Latos

sub-1.10 WHIP, 3.75+ SO/BB, 30+ Starts, 23 or younger (1900-present)
1910 Walter Johnson (Senators)
1966 Don Sutton (Dodgers)
1968 Tom Seaver (Mets)
1984 Dwight Gooden (Mets)
1985 Dwight Gooden (Mets)
1985 Bret Saberhagen (Royals)
2010 Mat Latos (Padres)

If Latos has ended his season on September 7th, it would have looked even better.  He went from 14-5 with a 2.21 ERA to being 14-10 with a 2.92 ERA after his final start on October 3rd.  Despite this, it was an exceptional season considering his age and he'll probably start finishing higher than 8th in the Cy Young voting this season.