Digne's powerful shot from 10 yards out beat substitute goalie Paulo Lopes, who got a hand to the blast but could not keep it out.
While some big names were missing, it was an entertaining affair that followed on the heels of Toronto FC's 2-1 win over the Philadelphia Union. The international friendly drew an announced crowd of 17,843 to BMO Field, compared to 25,032 for the MLS game.
Teenager Jean-Kevin Augustin and Brazil's Lucas Moura also scored for the French champions.
Brazil's Talisca and Jonas replied for Benfica, who came close to a tying goal in the 87th minute on a swerving shot by Nelson Oliveira that was pushed over the bar by substitute 'keeper Salvatore Sirigu.
The tournament features 15 teams in action in North American, Australia and China.
Strikers Zlatan Ibrahimovic, Edinson Cavani and Ezequiel Lavezzi, goalkeeper Nicolas Douchez, defender David Luiz and midfielders Thiago Motta and Marco Verratti were among the PSG players who did not make the trip to Canada as manager Laurent Blanc juggled his roster and gave his Copa America participants some time off.
Blanc was happy getting the win given his depleted roster.
"Don't forget there were a lot of young players on the pitch tonight," said Blanc.
"The young players played well," he added.
Benfica coach Rui Vitoria, like Blanc, spoke through an interpreter.
"Of course Benfica doesn't like to lose but this is the kind of game where you're observing players and correcting mistakes," he said.
Toronto fans did get to see 65 minutes of Benfica goalkeeper Julio Cesar, who started the 2014 season with Toronto FC before leaving the club after the World Cup.
Both teams made liberal use of their bench in the second half. Italian midfielder Bryan Cristante, a 20-year-old who also holds a Canadian passport through his Canadian-born father, came in late in the game for Benfica.
The pro-Portuguese crowd was solidly behind Benfica, which replaced Porto in the tournament in late May.
Benfica carried the play in the early going with German goalie Kevin Trapp having to hurl himself across the PSG goal to make a spectacular stop on Talisca, who seemed to be staring at an open goal as a cross went through the six-yard box from one side of the goal to the other.
Cesar, dressed in highlighter yellow above orange boots, was finally roused from his slumber in the 20th minute with a good save on Jean-Christophe Bahebeck, who made a smart turn to find room for the shot.
Cesar, frozen to the spot, was beaten in the 29th minute as the 18-year-old Augustin took a pass from Bahebeck, spun off a defender and fired a shot through the legs of another Benifica player into the goal.
Augustin scored twice in PSG's 3-0 pre-season win in Austria over Wiener SK.
Benfica answered four minutes later. Trapp stopped a hard shot from Jonas outside the penalty box but the ball deflected to Talisca, who hammered home an even harder shot from farther out.
The 21-year-old Brazilian hit the post in the 40th minute with another long-range rocket.
Jonas made it 2-1 with a tap-in in the 42nd. Argentine midfielder Nico Gaitan did the hard work on the goal, taking a through ball and dancing around the 'keeper before sending it to a wide-open Jonas.
Christophe Nkunku drew the 64th-minute penalty that tied the game at 2-2, when he was bodied to the ground by Benfica's Jardel. Lucas stroked the penalty home, with Cesar going the wrong way.
Based in New Jersey, PSG is holding an 18-day North American pre-season camp with future International Champions Cup games against Fiorentina, Chelsea and Manchester United as well as the Trophee des Champions match Aug. 1 against Lyon in Montreal.
PSG won France's Ligue 1 last season with a 24-3-11 record, outscoring its opposition 83-36. The free-spending club, owned by Qatar Sport Investments, made it to the quarter-finals of the Champions League before losing to eventual winner Barcelona.
Benfica also won its league comfortably, posting a 27-3-4 record.
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