Ten-player Aston Villa held out for a 0-0 draw against a relatively young, inexperienced Ajax side at the Johan Cruyff Arena, who were also reduced to 10 late on.
Ahead of next week's decisive return leg at Villa Park, Unai Emery's side exercised caution, clearly keen to enter the second leg in more familiar surroundings on an even footing. The hosts, meanwhile, applied a more attacking approach, spearheaded by tricky forward Brian Brobbey, and were far more willing to pursue an advantage to take to the Midlands.
Ajax, four-time European winners, fielded an XI containing nine starters under the age of 23, including Brobbey, who had the best chance of an uneventful first period when sprinting away from Ezri Konsa before spooning his effort into the side-netting.
The second period improved after the introduction of Matty Cash, Leon Bailey and John McGinn, restoring Villa close to full strength, but it was Ajax's Kenneth Taylor who came closest to a breakthrough, producing a smart low stop from Emi Martinez midway through the half.
Substitute Chuba Akpom also went close before tussling with Konsa and drawing a foul, with the latter receiving his marching orders for a second bookable offence and will miss next Thursday's second leg as a result.
The game became a little frenzied late on but Villa, Europa Conference League favourites, barely lay a glove, before Ajax full-back Tristan Gooijer also fell foul of Albanian referee Enea Jorgji and was dismissed four minutes before the end.