It was the Italians who took the lead after just three minutes with a clever lob from Niccolo Belloni, but Dortmund fought back strongly and were rewarded for their dominance on thirty-six minutes when Nick Weber's strike found it's way past Inter keeper Raffaele Dalle Vedove.
The German's pressed hard for the winner in the second half but Inter were resolute in defence and the game ended as a fair draw.
Tottenham Hotspur produced an outstanding display this evening to outclass FC Barcelona 4-1 at the Mini Estadi.
Shaquille Coulthirst completed a brilliant hat-trick on sixty minutes before Alex Pritchard added to the scoresheet 10 minutes later to take Spurs into a 4-0 lead.
Cristian Herrera grabbed a late consolation goal for the Catalans but it was a dominant display from the London side. T
The win takes Spurs top of Group 1, level on points with Barcelona, with one game remaining for both sides in the Group stage. Barcelona host Vfl Wolfsburg later this month whilst Tottenham host Anderlecht in December.
Aston Villa kept their qualification dreams alive with an impressive 2-0 victory over PSV Eindhoven.
Graham Burke chipped the keeper on twenty minutes to give Villa the lead and a calmly taken goal from Mikey Drennan on eighty-four minutes took the home side up into second in the Group. Villa travel to Lisbon later this month to play Sporting CP in a game that will determine the group winner.
Paris St. Germain move four points clear at the top of Group 2 with a 2-0 win over Fenerbahce.
The hosts took an early lead through Saiwtrimat, before adding to their lead from the penalty spot on sixty-five minutes after Fenerbahce's keeper Erten Ersu was sent off for a second yellow card. The French looked comfortable throughout the ninety minutes and were deserved winners.
PSG extend their lead in Group 2 to four points over Juventus.
The full time scores, and scorers, for the opening games were:
Borussia Dortmund 1 (Weber 36') vs. Internazionale 1 (Belloni 3')
FC Barcelona 1 (Cristian 88') vs. Tottenham Hotspur 4 (Coulthirst 25', 29' 60', Pritchard 72')
Paris St. Germain 2 (Saiwtrimat 7', Yaisien 65' PEN) vs. Fenerbahce 0 (Red Card - Ersu 64')
Aston Villa 2 (Burke 20', Drennan 84') vs. PSV Eindhoven 0