Victor Boniface gave Xabi Alonso’s side a deserved lead in the 51st minute by tapping in on the rebound after Milan keeper Mike Maignan had denied Jeremie Frimpong.

But Milan grew into the game and struck the bar with seven minutes remaining through Theo Hernandez’s deflected long-range effort. Spain striker Alvaro Morata also headed narrowly wide on the follow-up.

Leverkusen were the better side until the closing stages and had a goal ruled out in the first half.

Boniface also found the net after a fine Frimpong cross in the 21st minute, but the video assistant referee (VAR) ruled the Dutch wing-back had timed his run too early and was offside.

Leverkusen had thrashed Feyenoord 4-0 in their Champions League opener last month, while Milan were beaten 3-1 at home by Liverpool.

The result against Werder Bremen on Sunday was as emphatic as the club’s unbeaten juggernaut of a league campaign.

As Leverkusen fans poured onto the pitch to celebrate, the 23-year-old Nigeria striker had a message for them.

“We are celebrating a great achievement in the league but we still have two other competitions (the Europa League and German Cup final) to compete in and try to win for our fans,” he said.

It was fitting that Boniface began Sunday’s rout, given the way he got the ball rolling with a strong start to the season following his reported $25m (£20m) move from Belgian side Union Saint-Gilloise last July.

He scored eight goals in his first seven games across three different competitions, and then had another purple patch through December, notching five times in the space of three weeks in the run up to Christmas.

Having racked up 16 goals in all competitions, and established a strong understanding with club talisman Florian Wirtz, Boniface’s rollercoaster suddenly turned into a house of horrors.

A groin injury ruled him out of the Africa Cup of Nations just days before the tournament in Ivory Coast, where the Super Eagles eventually finished as runners-up.

“Only God knows why,” he posted on social media, before telling BBC Sport Africa: “There are some things that will happen, you can’t explain it because it’s beyond your own understanding”.

Europe and injuries

Nations Cup heartbreak was nothing new for Boniface, with the striker having missed out on 2019’s Under-20 Afcon because of another late injury.

Aged 18, he damaged his anterior cruciate ligament just weeks after moving to Europe to join Norwegian club Bodo/Glimt, complicating his adaptation to life in Scandinavia as well as robbing him of that formative appearance on the international stage with the Flying Eagles.

However, despite a second ACL injury, by the time he left the Eliteserien club in 2022 he had played a part in helping Glimt win two league titles.

Their 2020 triumph, in Boniface’s debut season, was the first time the club had ever finished top of the pile in Norway.

Sound familiar?

He then came agonisingly close to repeating the trick in his sole season in Belgium with Union Saint-Gilloise, with the club finishing second in the Pro League, behind champions Genk only on goal difference.

It would have been the club’s first title since 1935.

Boniface netted 15 times during that 2022-23 season, drawing particular praise for his performances and six goals in the Europa League as Union reached the quarter-finals.

The team that knocked them out? Bayer Leverkusen.

Leverkusen’s sporting director Simon Rolfes claimed the Germans were already interested before Boniface’s goal in the last-eight tie between the sides, but his strike in a losing cause at the BayArena did nothing to put them off.

But as people later found out, the European ride nearly went off the rails before it really built up speed.

The loss of his mother in 2019, as well as the two ACL injuries, damaged Boniface’s love of the game for a while, leading to alcohol abuse and even suicidal thoughts for a time while he was in Norway.

“I stopped paying attention to my diet and started partying,” he recalled.

“I was not even a drinker before then but I started drinking just to feel something. I was depressed and didn’t even realise it.”

Leverkusen’s African pride

From the lows of depression, Boniface’s rehabilitation has ridden to new levels at Bayer Leverkusen – but he has not been the only African making an impression as part of Xabi Alonso’s formidable side.

Ivory Coast’s Nations Cup winner Odilon Kossounou and fellow central defender Edmond Tapsoba of Burkina Faso have been stalwarts at the back, while Nigeria’s Nathan Tella and Morocco’s Amine Adil have largely been used as effective impact substitutes in attack.

The success of the quintet has seen widespread interest across Africa, with this season’s storyline possessing extra intrigue.

The 120-year-old club had previously been dubbed “Neverkusen” by fans in Germany due to its propensity for finding inventive new ways to come up short – not least when Leverkusen finished as runners-up in the league, domestic cup and Champions League in 2001-02.

But it is Boniface who has garnered most of the headlines, beating Bayern Munich’s $105m (£86m) new signing, England captain Harry Kane, to August’s Bundesliga Player of the Month award, as well as claiming four consecutive Rookie of the Month awards (August, September, October and November), an honour handed out to stars who are no older then 23 at the start of the league season.

Now fully recovered from his groin injury, Boniface has the chance to add two more pieces of silverware to his collection and looks to be hitting form again with two goals in his last two games.

First up is the second leg of Leverkusen’s Europa League quarter-final against West Ham in London on Thursday, with the Germans holding a 2-0 advantage.

The German Cup final against Kaiserslautern on 25 May will provide a glorious chance to end his maiden season with the club on another high.

“I have won a league title before,” Boniface said as the beer flowed freely in celebration at the BayArena on Sunday. “But this is different. This is bigger.”

The burly striker’s journey has been full of twists and turns so far but there is plenty more track ahead of him, including a tilt at next season’s newly-expanded Champions League – although he is already being linked with moves away from Germany.

For now, it is Leverkusen and Nigeria fans screaming about his success and it looks like Boniface wants to go faster.

The 23-year-old is the latest member of the Super Eagles squad to suffer an injury ahead of the tournament, which kicks off on 13 January in Abidjan.

Nice striker Terem Moffi has been called up to replace Boniface, pending the approval of the Confederation of African Football (Caf) and agreement with the player’s French Ligue 1 club.

Boniface now joins a growing list of Nigeria players who have been forced to miss Afcon 2023 through injury, including Nottingham Forest striker Taiwo Awoniyi and Leicester City midfielder Wilfred Ndidi.

Ndidi’s Leicester team-mate Kelechi Iheanacho, who missed the Super Eagles training camp, is expected to join up with the rest of the squad in Ivory Coast.

Huge miss for Nigeria

Boniface has been in good form for his German club with 10 goals and seven assists in the Bundesliga this season and is in the running to be named the Bundesliga rookie of the month for a fifth consecutive time.

He picked up the injury in Nigeria’s training camp in Abu Dhabi and was absent from the Super Eagles’ 2-0 friendly loss to Guinea on Monday.

He shared his disappointment with his followers on X, having also previously missed the Under-20 Africa Cup of Nations through injury.

Nigeria begin their quest for a fourth Afcon title in a Group A game against Equatorial Guinea on 14 January.

The West Africans will also face hosts Ivory Coast and Guinea-Bissau in the group stage.