Preview Martin Klizan scored one of the biggest wins of his career by defeating the former world #1 Novak Djokovic (struggling for form and fitness) in the second round of ATP Barcelona on Wednesday, 6-2 1-6 6-3.It was the Slovakian's fourth win of the week (entered the main draw as a qualifier) and the second consecutive three-set win.Overall, Martin Klizan has registered 21 wins so far in 2018 (21/6), which is quite impressive considering he could win only 17 matches in the entire 2017 season (17/21).Klizan has appeared here thrice in the past and making the semifinal once in 2015 (recent appearance) is his best result in this tournament.Though Martin Klizan has won the Indian Wells Challenger title and made the semifinal at Marbella Challenger in the opening four months of the new season, the last time he progressed to the quarterfinal of a tour-level event was in 2017 at Hamburg, where he defeated an experienced and left-handed local player, Mischa Zverev, in the round of 16 (will be facing the Spaniard Feliciano Lopez this week).Feliciano Lopez produced an unconvincing performance and needed nearly two hours and 30 minutes to defeat Dusan Lajovic in his second round match (R1 bye).The Spaniard faced round of 16 defeats in his previous three appearances here at Barcelona (2015, 2016 and 2017), and he will be hoping to break the trend this time around. In his previous 17 appearances at ATP Barcelona, only twice Feliciano Lopez has made it to the quarterfinal stages.These two players met once in the first round of ATP Rotterdam earlier this season when Feliciano Lopez prevailed in straight sets, 6-3 7-6.Martin Klizan has won twice as many matches as Feliciano Lopez so far in 2018, and he is the more talented of these two. But Lopez is cool-headed (Klizan's weak part) and is by far the better player tactically which