Parker made his Arsenal debut against Blackburn Rovers on 3 April 1926. This was the first match of 172 consecutive first-team matches for Arsenal, a club record that still stands today. Reliable and assured at the back, Parker soon became Arsenal captain, and skippered the club to their first Cup final in the 1926–27 season, which they lost 1–0 to Cardiff City. Parker's luck was better with his next trip to Wembley in 1929–30 as Arsenal beat Huddersfield Town 2–0 and Parker became the first Arsenal captain to lift the FA Cup trophy. He then played in Arsenal's 2–1 victory over Sheffield Wednesday in the Charity Shield at Stamford Bridge in October 1930.