Pep Guardiola's Manchester City opened the play-offs in dominant fashion, while Ajax and Dinamo Zagreb have their work cut out away from home.
In the first leg of Champions League qualifying play-offs, Manchester City all but assured their place in the group stage, thumping Steaua Bucharest 5-0 via Sergio Aguero's hat-trick on Tuesday.
Goals from Aguero and David Silva effectively settled the match for last season's semi-finalists before the interval, in Pep Guardiola's first European match in charge.
Although Aguero missed two penalties in the first 21 minutes, the Argentine forward still bagged his hat-trick in the closing 12 minutes, after Nolito made it 3-0 four minutes following the break at Arena Nationala.
Rostov claimed a surprise 1-1 draw away to Ajax, holding on to give themselves every chance of progressing.
Dmitri Kirichenko's Rostov claimed a vital away goal in the 13th minute, with Christian Noboa's free-kick finding its way past a flat-footed Jasper Cillessen.
Ajax got their deserved equaliser 25 minutes later, with Davy Klaasen converting the penalty after Cesar Navas' handball.
For all of Ajax's dominance with the ball, ending the match with 72 per cent possession, they could not play their way through a compact Rostov side, who head back to Russia with the tie in their hands.
Dinamo Zagreb continued their inconsistent form under new coach Zlatko Kranjcar, coming from a goal down to salvage a 1-1 draw at home to Red Bull Salzburg.
After a tight first half in which neither side could create significant openings, Red Bull took the lead just shy of the hour-mark through Jonathan Soriano, his deflected header wrong footing Dinamo keeper Eduardo.
Dinamo had the bulk of possession in search of an equaliser, but eventually equalised from the spot with 14 minutes remaining as Marko Rog dusted himself off to send Alexander Walke the wrong way.
Despite some testy moments in the second half, Borussia Monchengladbach eventually emerged from Bern with a comfortable 3-1 lead over Young Boys.
After a well-worked opener for Raffael in the 11th minute, Miralem Sulejmani's equaliser for Young Boys nine minutes after the break caused some panic within Andre Schubert's ranks.
Substitute Andre Hahn restored the lead, and calm, a minute after coming on before an Alain Rochat own goal created breathing room.
In Tuesday's other match, Andrija Pavlovic gave Copenhagen a 1-0 win at home to APOEL Nicosia.