Kimbrel set a major league record for saves by a rookie with 46. The hard-throwing right-hander earned all 32 first-place votes in balloting by the Baseball Writers' Association of America. Kimbrel outpointed Braves teammate Freddie Freeman.
"It definitely did surprise me," he said during a conference call from his vacation in Hawaii. "I expected it to be close."
"It's something I really wanted to win," Hellickson said by conference call from his home in Iowa. He said there were "three or four guys" equally deserving of the award.
The AL Cy Young Award will be announced Tuesday. Detroit ace Justin Verlander is expected to easily win.
Kimbrel was overpowering for much of the season, striking out 127 in 77 innings. He also anchored a dominant Braves' bullpen, pitching 79 games. He was 4-3 with a 2.10 ERA.
The 23-year-old Kimbrel made 38 straight appearances in midseason without allowing a run. He seemed to wear down a bit in the stretch as the Braves frittered away a 10½-game lead in the NL wild-card race. His eighth blown save of the year came in the final game of the season, when he gave up the tying run in the ninth inning against Philadelphia. The Phillies went on to win in 13 innings, costing the Braves a spot in a one-game playoff against St. Louis for the wild-card slot.
"I'm going to get over it, but I'm not going to forget it," he said. "I need to fix it."
Kimbrel wound up tied for Milwaukee's John Axford for the NL lead in saves. He became the 10th unanimous NL rookie winner, and first since Albert Pujols in 2001. Kimbrel was the seventh Braves player to win the award that began in 1947, and first since Rafael Furcal in 2000.
Kimbrel, who pitched 21 games in 2010 but still retained his rookie eligibility, earned 160 points in the BBWAA balloting. Freeman, who hit .282 with 21 home runs and 76 RBIs, was second with 21 second-place votes and 70 points. Kimbrel and Freeman became the first pair of teammates to finish 1-2 in the NL rookie voting since Cubs outfielders Jerome Walton and Dwight Smith in 1989.
Philadelphia pitcher Vance Worley was third and Washington catcher Wilson Ramos was fourth. Ramos was kidnapped in Venezuela last week and freed Saturday when commandos raided the mountain hideout where he was being held.
Hellickson was a big reason the Rays were able to erase a nine-game deficit against Boston in the last 3½ weeks to win the AL wild-card spot. He was unbeaten in five starts against AL East teams in the final month, and finished 7-3 in games against division rivals.
The 24-year-old Hellickson is generously listed at 6-foot-1, but held up extremely well over 29 starts. He led all big league rookies in ERA, innings (189) and opponents' batting average (.210).
Hellickson, who went 4-0 in 10 for the Rays in 2010, joined Evan Longoria (2008) as Tampa Bay players to win the AL rookie honor. Hellickson finished with 102 points.
Trumbo drew five first-place votes and 63 points. Eric Hosmer, who hit .293 with 19 home runs and 78 RBIs after being called up by Kansas City in May, got four first-place votes and 38 points. Ivan Nova, 16-4 with a 3.70 ERA for the New York Yankees, got one first-place vote and was fourth with 30. Seattle second baseman Dustin Ackley drew the other first-place vote.