[1] Four years later, on 2 October 2018, he made his first team debut in a Czech Cup match against Slavoj Polná [cs] as a substitute, scoring the final goal in a 4–1 away win.

[3][4] Hložek finished the 2020–21 Czech First League as joint top scorer, alongside Jan Kuchta with 15 goals, despite missing four months of the season due to injury.

[5] On 30 May 2021, a day after scoring four first-half goals in a 6–1 away victory against Zbrojovka Brno, Hložek signed a new contract extension until 2024 with Sparta Prague.

[20] After returning from an ankle injury which had him ruled out for a month, he provided a hattrick of assists against Eintracht Frankfurt in a 5-1 victory on 5 May 2024 and grabbed man of the match.

[21] Hložek played in the 2023–24 UEFA Europa League final with a shot outside the box in the last 20 minutes, but could not score and Leverkusen lost their 51-game unbeaten streak after losing 3-0 to Atalanta BC.

[24] Adam missed out on the next two games due to thigh problems but right after he scored his first goal for the club on matchday 5 on September 21st, 2024 against Werder Bremen but also Hoffenheim lost 4-3.

[28] In the next matchday Hlozek could have scored another brace but was called offside for the first but then he responded with a quickfire assist and a dramatic late volley goal in the 96th minute to secure a 2-2 draw.