He signed his first professional contract with the club and made his debut during the 1998–99 season, at the age of 18. He won the Bulgarian Cup with CSKA at the end of that season. Berbatov's first game in Europe came in September 1999, in a 2–0 defeat against his childhood team Newcastle United; it was during that season, 1999–2000, that he started to make his name, scoring 14 goals in 27 league matches. On 24 August 2000, Berbatov scored five goals in the 8–0 home win over Constructorul Chișinău in a UEFA Cup first qualifying round match, becoming the only CSKA Sofia player to manage this feat in a single game in the European tournaments. Berbatov nearly signed for Italian side Lecce in June 2000, even passing a medical before the move collapsed at the last minute. Bayer Leverkusen A run of nine goals in eleven games during the first half of the 2000–01 season was enough to persuade German club Bayer Leverkusen to pay €1.3 million to sign a four-year contract with Berbatov on 1 January 2001. Berbatov played for the club's reserve team in the Oberliga Nordrhein at first, and scored six goals in seven appearances before being promoted to the first team. He made his team debut in a 4–3 pre-season friendly win against D.C. United, scoring a hat-trick. His league debut for the first team came on 10 February 2001, replacing Ulf Kirsten in a 4–1 victory against 1. FC Köln. Berbatov found himself being used as a substitute by manager Berti Vogts, making six appearances and scoring no goals as Leverkusen finished fourth and qualified for the following season's UEFA Champions League. During the next season, Berbatov scored 16 goals and made important contributions to the club's Champions League campaign, scoring in a 4–2 win over English club Liverpool in the quarter-finals as Leverkusen eventually reached the final. In the final itself, against Real Madrid, Berbatov came on as a substitute for Thomas Brdarić after 38 minutes before Leverkusen lost 2–1. Leverkusen also finished as runners-up in the Bundesliga behind Borussia Dortmund, and lost the DFB–Pokal final 4–2 to Schalke 04, thus completing an unusual treble of runners-up finishes. Berbatov established his place as the first-choice forward during the next season, 2002–03, and netted his team's goal against Manchester United on 24 September 2002, during a 2–1 defeat for Leverkusen. He scored 16 goals