West Ham United were held to a surprise draw against Astra Giurgiu of Romania at Upton Park, with the Londoner's hopes of progression now hanging by a thread.
The visitors grabbed two late goals to take the draw and now have a great chance of beating the Premier League side in the return leg on August 6.
There were mandatory wins on Thursday night for Bundesliga giants Borussia Dortmund and EPL side Southampton, as well as a win for La Liga's Athletic Bilbao.
Read on for the full list of results from the first legs of the third qualifying round:
| Home | Score | Away |
| Kairat Almaty | 2-1 | Aberdeen |
| IF Elfsborg | 2-1 | Odd |
| AIK | 1-3 | Atromitos Athens |
| Apollon Limassol | 1-1 | FK Qabala |
| Altach | 2-1 | Vitoria Guimaraes |
| FK Krasnodar | 2-0 | Slovan Bratislava |
| PAOK Salonika | 1-0 | Spartak Trnava |
| Sturm Graz | 2-3 | Rubin Kazan |
| Slovan Liberec | 2-1 | Hapoel Ironi Kiryat Shmona |
| AZ Alkmaar | 2-0 | Istanbul Basaksehir |
| FC Thun | 0-0 | FC Vaduz |
| FC Zurich | 0-1 | Dinamo Minsk |
| MSK Zilina | 2-0 | Vorskla Poltava |
| ASA Targu Mures | 0-3 | St Etienne |
| Brondby | 0-0 | Omonia Nicosia |
| Debrecen | 2-3 | Rosenborg |
| FK Kukes | 1-2 | Legia Warsaw |
| Rabotnicki | 1-0 | Trabzonspor |
| Bordeaux | 3-0 | AEK Larnaka |
| Sporting de Charleroi | 0-2 | Zorya Luhansk |
| Standard Liege | 2-1 | Zeljeznicar Sarajevo |
| Athletic Bilbao | 2-0 | Inter Baku |
| West Ham | 2-2 | Astra Giurgiu |
| Belenenses | 2-1 | IFK Goteborg |
| Hajduk Split | 2-0 | Stromsgodset |
| Sampdoria | 0-4 | FK Vojvodina |
| Wolfsberger AC | 0-1 | Borussia Dortmund |
| Southampton | 3-0 | Vitesse |
(A full list of second leg fixtures can be found at UEFA.