Brahim Diaz scored Milan’s first goal in the knockout stage of the competition to win the match since Kaka in 2014.
Diaz, after his save from Forster’s superb double by Fraser, just seven minutes later he bunched the ball across the line.
Unable to really test their Serie A opponents, the Spurs struggled to hold their own in the final third.
But they are happy to concede just one goal in the second leg next month.
Indeed, Antonio Conte will be without Eric Dier after being booked.
Tottenham will have to produce a Champions League comeback after Brahim Diaz gave AC Milan a narrow win in the first leg of their last-16 tie at the San Siro.
Diaz nodded in early on after Spurs goalkeeper Fraser Forster had saved a Theo Hernandez shot and then superbly got a hand on the scorer’s initial follow-up attempt.
Antonio Conte’s side looked relatively comfortable for long periods of the contest against the seven-time European champions – as a youthful pairing of Pape Sarr and Oliver Skipp deputised ably for the suspended Pierre-Emile Hojbjerg and the injured Rodrigo Bentancur in midfield.
However, they were rarely able to build any attacking momentum with their front three of Harry Kane, Son Heung-min and, until his withdrawal, Dejan Kulusevski well shackled by a disciplined home defence.
Aside from ambitious long-range efforts from Emerson Royal and Sarr, Conte’s side appeared most capable of threatening from set-pieces but neither Kane nor Eric Dier were able to direct headers on goal from two excellent Son deliveries.
In the end, Spurs were grateful for the profligacy of the hosts as Belgian midfielder Charles de Ketelaere and German defender Malick Thiaw both headed excellent opportunities – to put the Italian side firmly in control of the tie – wide. Had either pair nodded from close range, the Spurs would have faced an even more difficult salvage operation in the second leg in London on Wednesday 8 March.
Therefore, it must be a draw without Dyer, who was suspended for late bookings.
Milan continue bounce back against Spurs
They don’t have the star quality or pride of Milan’s big team, but they have shown a lot of know-how to carve out a small advantage.
Their only regret is that although they had good competition, they weren’t able to pass a Spurs team who gave little help in the final third.
A place in the quarter-finals is at stake anyway, but Conte has yet to find a way to make up for the absence of Uruguay international Bentancur, who has been a key player since joining from Juventus 12 months ago.
The Italian will also demand more diligence from his side in defence, as Argentina’s Cristian Romero is sure to come under scrutiny for his role in Milan’s victory.
The World Cup-winning centre-back was upset when Hernandez overtook him in the run-up to the home side’s goal. He was later admonished for an inappropriate fight with the feisty Raphael Leo. With Spurs trying to prevent Milan from reaching the quarter-finals for the first time since 2012, stopping the Portugal international’s menacing run in the second leg is vital for hopes.
Sarr and Skipp impress but Romero, Son and Kulusevski poor
Made two saves in the move that led to Diaz’s early headed goal, the second a wonderful reaction stop but nobody was covering the Milan attacker. He didn’t have too much else to do with the hosts send two late good chances wide.
Beaten easily in the air by Hernandez in the build-up to Diaz’s early goal with the Milan man then able to collect the ball himself and run on. The same player breezed past him before the break but his cross was deflected behind the goal this time. He was then booked for a flying late tackle on Tonali. Not a good night on his return to the team.
A busy presence down the right and also tucked in to help the young midfield duo in the centre of the pitch at times. Sent a central shot at the keeper 25 minutes in.
A real workhorse in the centre of the pitch, reading the game well and making a number of interceptions. Looked much more like his old (young) self.
Pape Matar Sarr
His Champions League debut and he looked comfortable and composed alongside his only slightly older midfield team-mate. Almost a nine and Spurs’ man of the match on the day.
The 34-year-old showed his fitness to get up and down the pitch just three days after the Leicester game. Needed some more quality in his delivery.
Struggled to make any real impact on the game in his 70 minutes on the pitch as he returned to Italy to face an opposition he knows well.
Battled away up front and held the ball up well most of the time but had precious little service to work with.
Another one of those games in which he struggled to make any inroads and he loses the ball sloppily at times, one occasion earning him a rollicking from Dier. Put in a couple of dangerous free-kicks but that was about it.
Add some fresh legs down the right for the final 20 minutes but no more quality than Kulusevski.
Came on for Son and was also a willing runner but nothing really fell his way.