Leverkusen are unbeaten in all competitions this season.

Invincibles

Alonso's side lead Bayern Munich by 16 points with five games remaining after 25 wins and four draws in the Bundesliga this season.

Wins or draws against all of Borussia Dortmund, Stuttgart, Eintracht Frankfurt, Bochum and Augsburg would see them complete the first ever undefeated Bundesliga season - Bayern lost just one game in both the 1986-87 and 2012-13 seasons, a record in the competition.

Leverkusen are also in the DFB-Pokal final, against second-tier Kaiserslautern, and hold a 2-0 lead from the first leg of their Europa League quarter-final against West Ham.

They have not lost in those competitions either, with an overall season record of 38 wins and five draws, 123 goals scored and only 31 conceded.

Sunday's title-clinching 5-0 win over Werder Bremen was the fifth time this season they have scored five goals - Darmstadt, third-tier Sandhausen and European opponents Qarabag and Molde the other victims - in addition to an 8-0 cup rout of fourth-tier Teutonia Ottensen.

Florian Wirtz's hat-trick against Bremen moved him alongside Victor Boniface as the club's leading scorer, both with 11 league goals and 17 in all competitions. Leverkusen have kept 21 clean sheets at the other end.

Arsenal's 2003-04 team earned the title of "The Invincibles" after winning the Premier League without losing a match - Alonso's men need to get through a further nine or 10 games to complete an "Unbesiegbar" season across all competitions.

Xabi's X-factor

Taking over a team second-bottom of the table in October of last season, Alonso worked wonders to lead Leverkusen to a sixth-placed finish and a Europa League semi-final before breaking new ground this season.

Across his 80 games in charge to date, Alonso has 55 wins - a remarkable 68.8 per cent rate - with 15 draws and 10 defeats. His side have scored 187 goals, averaging 2.34 per match, and conceding 77 or just under a goal per game.

Alonso was linked with Tottenham last summer and with the upcoming vacancies at Liverpool and deposed Bundesliga champions Bayern Munich - both clubs he represented as a player - at the end of this season.

He has pledged his continued loyalty to Leverkusen, who will be hoping that remains the case as his stock rises.

By the numbers: Xabi Alonso's invincible Bayer Leverkusen streak