Milan Skriniar was Inter's matchwinner as his goal secured a hard-fought 1-0 victory over Atalanta, moving the Nerazzurri clear at the top.
Inter lead the way in Serie A but Antonio Conte knows there is still much work to do in pursuit of a first Scudetto since 2010.
Gianluigi Donnarumma is yet to re-sign with Milan and Chelsea have reportedly readied a contract to swoop.
Real Madrid lacked creativity in a poor game at Atalanta but Zinedine Zidane was pleased with the way they stuck to the task.
Zinedine Zidane mengakui faktor kecederaan tidak memihak Real Madrid ketika hanya meraih kemenangan tipis 1-0 ke atas Atalanta dalam Liga Juara-Juara Eropah (UCL) awal pagi tadi.
Injury-hit Real Madrid will start the second leg against Atalanta with the edge after Ferland Mendy's late winner.
After heartbreak on the field and tragedy off it, Atalanta are back in the Champions League knockout stages and gunning for Real Madrid.
Real Madrid head to Atalanta and Borussia Monchengladbach host Manchester City in Wednesday's Champions League ties.
Real Madrid have fallen at the last 16 in the previous two Champions League seasons and Zinedine Zidane knows Atalanta present a danger.
Injury-hit Real Madrid have been linked with both Kylian Mbappe and Erling Haaland but will have neither against Atalanta.