Bobby Cramer, a former substitute teacher who started this season in the Mexican League, won his big league debut Monday by pitching the Oakland Athletics over the Kansas City Royals 3-1.

Cramer held the Royals to one run and four hits in 5 1-3 innings. He struck out four and walked one.

Cramer (1-0), a left-hander who turns 31 next month, started his pro career in 2003 in the Tampa Bay system. He was a high school math teacher and worked in pipeline maintenance while out of baseball in 2005-06, and played in an independent league in 2008.

This year, Cramer went 13-3 with a 2.95 ERA in 22 games with Quintana in Mexico.

Cramer became the oldest pitcher in Athletics franchise history to make a start in his big league debut since Steve Gerkin for the Philadelphia A's on May 13, 1945.

Andrew Bailey worked the ninth for his 24th save in 27 opportunities.

Jack Cust hit his 100th home run, connecting in the Oakland sixth off Bryan Bullington. It was Cust's 11th home run this season.

Mike Aviles homered in the fourth for the only run off Cramer. Aviles hit his first home run since May 9, a span of 316 at-bats, and finished with three of the Royals' seven hits. Kansas City has lost nine of 11.

Luke Hochevar (5-5) lost in his first start since missing nearly three months with a sprained right elbow. He gave up two unearned run and two hits in five innings. He walked three and threw just 39 strikes in 78 pitches.

The A's took advantage of sloppy Royals fielding to take an early lead.

In the first inning, Aviles and Hochevar made errors and rookie catcher Lucas May was charged with a passed ball. Aviles' wild throw from second base on what could have been a double-play grounder by Kurt Suzuki allowed Coco Crisp to score.

Crisp began the game reaching on Hochevar's error and stealing second. Crisp has stolen at least one base in five straight games, totaling nine in that span, to run his total to a career-high 32.

Crisp's string of 24 steals ended in the fifth when he was caught trying to swipe third base.

Royals center fielder Jarrod Dyson, making his first big league start, dropped Cliff Pennington's fly in the second for an error that let Aki Iwamura score. Iwamura walked, moved up on Hochevar balk's and came home with two outs.

Notes: KC utilityman Willie Bloomquist was pulled from the starting lineup and traded to the Cincinnati Reds. The Royals will receive a player to be named or cash. ... The A's transferred OF-1B Conor Jackson, who had sports hernia surgery Sept. 1, to the 60-day disabled list to make roster space for Iwamura, who was signed as a free agent. Iwamura started at third as 3B Kevin Kouzmanoff missed his seventh straight game with lower back spasms.