Coach Antonio Conte ran onto the pitch to celebrate with his players as the goal restored Inter's 11-point advantage over second-place AC Milan, which won 3-1 at Parma on Saturday.
Darmian will be on loan until the end of June at which point he will join Inter on a permanent deal with the fee reported to be 2.5 million euros ($2.9 million).
Serie A: Cristiano Ronaldo's brace against Parma helps Juventus go four points clear at top; Inter Milan held by Lecce
Cristiano Ronaldo scored twice as Juventus beat Parma 2-1 on Sunday to remain firmly on course for a record-extending ninth straight Serie A title.
Sevilla sign striker Javier Hernandez from West Ham; Matteo Darmian leaves Manchester United to join Parma
Mexican striker Javier Hernandez has joined Sevilla from West Ham on a three-year deal, the Spanish club announced on Monday.
Premier League: Manchester United boss Ole Gunnar Solskjaer says he would have welcomed Zlatan to Old Trafford if he was turning 28, not 38
Zlatan had suffered a cruciate knee ligament injury and failed to recover his place in the side after Lukaku's arrival, triggering his 2018 move to LA
Premier League: England's center back Harry Maguire is Manchester United's prime target, according to reports
Harry Maguire is believed to want to secure the move although Leicester's Thai owners are reluctant to sell after another of their stars Algerian forward Riyad Mahrez moved to champions Manchester City
Romero usually is in goal for FA Cup matches but if he is not available, first-choice David De Gea should take his place under the bar against Spurs.
FIFA president Gianni Infantino feels Italy's failure to qualify for 2018 World Cup is a wake-up call
Infantino said that there had been signs of trouble within the four-time world champions long before their dramatic failure in last November's play-offs.
Mourinho adopted the same policy in the last winter transfer window when he agreed to requests from Morgan Schneiderlin and Memphis Depay to leave the club to pursue regular first-team football elsewhere.
FIFA World Cup 2018 qualifiers: Italy on brink of elimination after Sweden clinch win in play-off's first leg
Gian Piero Ventura's Italy will need to respond in Monday's return leg at the San Siro in Milan to avoid becoming only the second Azzurri outfit to fail to reach the finals.
FIFA 2018 World Cup qualifiers: Italy failing to qualify would be catastrophic, says coach Giampiero Ventura
"I'm not thinking about the play-offs, we need to think about the next two matches and then based on who we meet we'll weigh things up," said Ventura.
Premier League: Arsene Wenger's maiden win over Jose Mourinho could rekindle faith among Arsenal faithful
Arsenal's comfortable win over Manchester United is a thumping response to critics who believed Arsene Wenger is finished and must leave the club.
Manchester United manager Jose Mourinho said he, his players and even the club's supporters will need to raise their game when arch rivals Liverpool visit Old Trafford this weekend.
Jose Mourinho has warned Wayne Rooney he cannot be sure of being involved in Manchester United's clash with Crystal Palace on Wednesday despite Henrikh Mkhitaryan's injury
Manchester United manager Jose Mourinho faces a touchline ban after being charged with misconduct for the second time in less than a week by the Football Association (FA) on Tuesday.
Tears rolled down the cheeks of Gianluigi Buffon but the legendary Italy 'keeper said there were "no regrets" despite the Azzurri missing a golden chance to beat Germany to a Euro 2016 semi-final spot.
Manuel Neuer says his determination to stop Leonardo Bonucci's second spot-kick of the evening was the key to Germany's dramatic 6-5 penalty shoot-out win over Italy in Saturday's Euro 2016 quarter-final.
Lesser possession. Fewer chances. No superstars. Greater accuracy. Clinical decision making. Selfless spirit. Antonio Conte and his Italy are starting to demonstrate their fabled art of doing more and more with less.
Jesse Lingard's extra-time thunderbolt earned Manchester United a record-equalling 12th FA Cup as Louis van Gaal's side came from behind to defeat Crystal Palace 2-1 in Saturday's final at Wembley.
Manchester United will attempt to salvage something from their tumultuous season -- and potentially keep manager Louis van Gaal in a job -- in Saturday's FA Cup final against Crystal Palace.