Filippo Inzaghi broke Portsmouth’s hearts with a stoppage-time equaliser for AC Milan at Fratton Park last night. Tony Adams’s injury-hit side were seconds from an historic victory over the seven-times winners of the European Cup until the Italy forward, unmarked, brought down a hopeful lob forward from Gianluca Zambrotta and beat David James from close range.

Second-half goals from Younès Kaboul, his first for the club, and Kanu, in his first start since the FA Cup Final last season, had given Portsmouth what appeared a decisive lead in this Uefa Cup group E game. But Ronaldinho, who had come off the bench to replace a subdued Kaká, pulled a goal back with a sublime free kick and Inzaghi’s late strike completed a remarkable comeback.

Portsmouth had paid a heavy price for failing to heed a number of warnings from Inzaghi, who had already put three efforts against the woodwork, and it was only a question of whether the final whistle or a goal for the striker would come first.

Adams, though, put a positive spin on events. “I’m really proud of the guys,” he said. “It was an exceptional display. It’s my job to be really upbeat, and I am. I’m not the slightest bit disappointed. The guys are — they are a bit flat in there because they wanted some reward for their hard work, but that was probably the best performance since I’ve been at the club.”

Carlo Ancelotti, the Milan coach, admitted that his team had been fortunate to claim a point. “We almost lost hope, but to come back like that was really good,” he said. Was he surprised by the Portsmouth performance? “No, they always play like that at home,” he said. “We played well in the first half, but things got difficult after they took the lead.”

However commendable a result this was for Portsmouth, they have only one point to show from two matches in the group stage. They may have to win their remaining games — away to Wolfsburg next Thursday and at home to Heerenveen on December 17 — if they are to progress. “It’s going to be difficult to get through, but we can pick up points against Wolfsburg,” Adams said.

Milan have recorded only one victory on English soil in 14 attempts, a 1-0 success against Manchester United in Februrary 2005, but their point last night was sufficient to guarantee their passage into the knockout phase.

They made nine changes from the team who had started the 2-2 draw away to Torino at the weekend, but as reserve sides go it did not look too shabby, with Champions League and World Cup winners among them, including Kaká, the 2007 world and European player of the year, and a former European player of the year in Andriy Shevchenko. It was no surprise that they dominated the early stages.

After ten minutes, Shevchenko’s free kick ricocheted off the defensive wall to Inzaghi, whose snatched shot trundled past a wrong-footed James but bounced off the foot of an upright and back to the relieved goalkeeper.

Shevchenko shot weakly when well placed after 17 minutes and Inzaghi went through on Emerson’s pass seven minutes later, outpaced Sylvain Distin and lobbed the onrushing James. Fortunately for Portsmouth, the ball dropped on to the crossbar and behind. Then Kaká shot surprisingly high and wide after Armand Traoré’s attempted clearance sent the ball across his own goal.

Portsmouth, although without Jermain Defoe, Lassana Diarra, Sol Campbell and Niko Kranjcar, and with only six men fit enough for the bench, came back strongly. Ancelotti had singled out Peter Crouch as the player to whom his defenders needed to pay closest attention and the England forward had Portsmouth’s best chances of the first half, mis-hitting a volley from Kanu’s cross and nodding the ball into Dida’s hands from Johnson’s bouncing ball, as well as heading over from another cross by Johnson.

Milan were not heeding the role that Johnson was playing in Portsmouth’s increasing attacks and when the breakthrough came after 61 minutes, it was the defender who was at the centre of events. Milan failed to clear his free kick and Kanu kept the ball in play and returned it to him. A first-time cross found Kaboul, the former Tottenham Hotspur player, who headed down past Dida’s right hand.

If there was disbelief mixed with joy as the ball hit the net, there was delirium 11 minutes later, when Portsmouth doubled their lead. Johnson was again pivotal, skipping past tackles on the right before hitting the ball low across goal where Kanu slid in to score.

Fratton Park erupted but Milan continued to probe and when Johnson was punished harshly with a free kick for a challenge on Ronaldinho 30 yards out, the Brazil player got up to punish him again, curling the free kick beyond James. Even then, Portsmouth looked capable of holding out until Inzaghi made his final chance count.

What would Adams give for such attacking options? “I’m happy with what I have,” he said. “Those lads have given me everything they’ve got.”