Berlin, Feb 24 : Union Berlin advanced into the UEFA Europa League last-16 for the first time after clinching a 3-1 win over Ajax Amsterdam at the play-off second leg on late Thursday night. Both teams started highly motivated and staged a lively opening period. Clear-cut opportunities were at a premium, but that changed with 20 minutes gone as Ajax's Calvin Bassey conceded a handball penalty. Robin Knoche stepped up and kept his cool from the spot after beating Ajax goalkeeper Geronimo Rulli with the assistance of the inside post, a Xinhua report said. Ajax had to wait until the 40th minute to create danger in front of the target, but for all that, Mohammed Kudus pulled wide from five meters with all time and space. The Dutch visitors could have opened their scoring three minutes later, but Kudus' equalizer was flagged offside. At the other end of the pitch, Josip Juranovic's curl shot caught Rulli flat-footed, making it 2-0 just before the break. Ajax came out with its guns blazing after the restart and halved the deficit early in the second half when Kudus latched onto Steven Bergwijn's cross in the 47th minute. Union remained unimpressed, though and restored its two-goal lead three minutes later through Dutchman Danilho Doekhi, who hammered Juranovic's whipped corner to the back post into the roof of the net from close range. Ajax's resistance was broken, whereas Union's Sheraldo Becker left two presentable chances unused in the closing stages. Frustrated, Ajax had to complete the match with ten men as Edson Alvarez received his marching orders for unsportsmanlike conduct in the dying minutes of the game. "It can't get any better now. I am so proud. The boys showed great will and mentality against Ajax. Of course, you always need some luck to win these games," said Union coach Urs Fischer. /IANS