A cikin bazara na 1208, sojojin Bulgaria sun mamaye Thrace kuma suka ci nasara a kusa da Beroe (Stara Zagora na zamani).An yi wahayi, Boril ya yi tafiya zuwa kudu kuma, a ranar 30 ga Yuni 1208, ya ci karo da babban sojojin Latin .Boril yana da sojoji tsakanin 27,000 zuwa 30,000, daga cikinsu sojojin dawakai 7000 na Cuman, sun yi nasara sosai a yakin Adrianople.Adadin sojojin Latin kuma kusan mayaƙa 30,000 ne, waɗanda suka haɗa da mayaka ɗari da yawa.Boril ya yi ƙoƙari ya yi amfani da dabarun da Kaloyan ya yi amfani da su a Adrianople - maharba masu hawa sun tursasa 'yan Salibiyya da ke ƙoƙarin shimfida layinsu don jagorantar su zuwa ga manyan sojojin Bulgaria.Mahukuntan, duk da haka, sun koyi darasi mai ɗaci daga Adrianople kuma ba su maimaita kuskuren ba.A maimakon haka, sai suka shirya tarko suka kai hari ga rundunar da Tsar ya umarta da kansa, wanda ke da maza 1,600 kawai kuma ba zai iya jure wa harin ba.Boril ya gudu kuma duk sojojin Bulgaria sun ja da baya.Bulgeriya sun san cewa abokan gaba ba za su kore su zuwa cikin tsaunuka ba don haka suka ja da baya zuwa daya daga cikin mashigin gabas na tsaunin Balkan, Turia.'Yan Salibiyya da suka bi sojojin Bulgaria an kai musu hari ne a wata kasa mai tudu kusa da kauyen Zelenikovo na wannan zamani da masu gadin Bulgariya suka yi, kuma bayan wani kazamin fada da aka yi, an fatattaki su.Duk da haka, samuwarsu bai ruguje ba yayin da manyan sojojin Latin suka iso kuma aka ci gaba da gwabzawa na tsawon lokaci har sai da Bulgeriya suka koma arewa bayan yawancin sojojinsu sun bi ta tsaunuka cikin aminci.Daga nan ne 'yan Salibiyya suka koma Philippopolis.