Arrieta recorded a career-high seven strikeouts over seven dominant innings Saturday as the Norfolk Tides held on for a 4-2 victory over the Charlotte Knights.
The 24-year-old right-hander remained virtually untouchable after limiting the Knights to a pair of singles and a walk. He did not allow a runner past first base and surpassed his previous high for strikeouts, set in 2008 at Class A Advanced Frederick and equaled last May 16 for Double-A Bowie.
Arrieta lowered his International League-leading ERA to 0.36. In four starts, he has given up one earned run on 13 hits over 25 innings while limiting opponents to a .157 batting average.
The former fifth-round pick outdueled Carlos Torres, MLB.com's 2009 Triple-A Starting Pitcher of the Year, who struck out 10 and gave up four runs on three hits in seven innings.
The Tides staked Arrieta to the lead in the third on Adam Donachie's second homer of the season. They padded it an inning later when Scott Moore launched a three-run shot, his second.
Arrieta (2-0) came out after throwing 63 of 95 pitches for strikes. Armando Gabino breezed through the eighth before putting two runners on in the ninth. Frank Mata gave up a two-run single to Tyler Flowers, then recorded the final two outs and wrapped up Norfolk's second win in a row.