Viking FK recovered from two goals down to draw 2-2 at Dinamo Zagreb on Tuesday, as all three of the night's Champions League playoff first legs ended without a winner.
Fenerbahce drew 1-1 with Olympique Lyon in Istanbul, while Levski Sofia held AEK Athens to a goalless draw in Bulgaria.
The playoff round is the final qualifying stage before the league phase of Europe's premier club competition. The return legs will be played on August 25 and 26.
Viking comeback
Dinamo Zagreb took the lead in the sixth minute in Croatia. A cross from Moris Valincic was deflected by a Viking defender into the path of Matteo Perez Vinloef. The Swedish player's powerful strike hit the chest of Dinamo striker Dion Drena Beljo and rebounded into the net.
The hosts doubled their advantage four minutes later following a mistake by Viking's Henrik Saelebakke Falchener. Beljo intercepted the ball and advanced before passing to Mateo Lisica, who finished easily.
The Norwegian champions responded in the 26th minute. Dinamo midfielder Josip Misic cleared the ball to Tobias Moi, who found Peter Christiansen in the penalty area. The Danish forward scored with the outside of his foot past goalkeeper Ivan Nevistic.
Viking equalised shortly before half time. Moi provided another assist, setting up captain Zlatko Tripic to strike into the far corner of the net.
Dinamo controlled possession in the second half but were unable to score a third goal against goalkeeper Arlid Oestboe.
Greenwood scores in Istanbul
In Turkey, Fenerbahce fell behind to French side Lyon in the 40th minute. Corentin Tolisso delivered a cross from the right side of the penalty area, and Lois Openda scored with a diving header.
Mason Greenwood equalised for the hosts shortly after the break. The English forward received a pass from Kerem Akturkoglu, beat a defender and scored with his left foot past Dominik Greif.
Fenerbahce substitute Dorgeles Nene hit the post with a left footed shot in the 73rd minute.
Levski hold AEK
In Sofia, Greek side AEK Athens dominated the early stages against Levski. Luka Jovic hit both the crossbar and the post of Svetoslav Vutsov's goal in the first half from passes by Lovro Majer.
Levski's El Mehdi Moubarik shot straight at goalkeeper Thomas Strakosha from a promising position before the interval.
The Bulgarian hosts defended deeply in the second half, with centre backs Kristian Dimitrov and Nikola Serafimov helping to secure a clean sheet.
Four more playoff first legs are scheduled for Wednesday, featuring Celtic against LASK Linz, Hapoel Beer Sheva against Sabah Baku, NEC Nijmegen against Bodo/Glimt, and Slovan Bratislava against NK Celje.
