Denys Oliynyk headed FC Metalist Kharkiv's winner in first-half added time but the Ukrainian side had to weather some intense second-half pressure from UC Sampdoria before coming away with a valuable victory.
After a cautious start by both teams, Metalist threatened in the 20th minute when Jajá drilled in a 25-metre shot which Sampdoria goalkeeper Luca Castellazzi did well to save. The visitors went closer still five minutes later when Valentyn Sliusar sent a miscued shot over the bar from six metres, while Jajá continued to try his luck from distance, though his efforts barely troubled Castellazzi. Just when it looked as if it was going to end all-square at half-time, Metalist broke the deadlock as Oliynyk rose highest in the box to head home Olexandr Rykun's cross from the left.
Sampdoria began the second half a far more determined side as they fought for an equaliser and almost restored parity within ten minutes, Claudio Bellucci's attempt being blocked by Metalist defender Papa Gueye. The Italian outfit almost fell further behind seconds later, though, and needed Castellazzi to pull off a great stop to keep out another Oliynyk header.
Paolo Sammarco came on for Sampdoria shortly before the hour mark and nearly had an instant effect as his 12-metre volley scraped the top of the crossbar. The Serie A team were laying siege to their opponents' goal and Andrea Raggi should have levelled in the 71st minute with a header that flew wide from close range. Instead, Metalist's victory put the Ukrainian club firmly in the driving seat for next week's second leg and also ended Sampdoria's unbeaten home record in this season's competition.