《旧唐书·列传·卷四》
过了五天，杨义臣果然大败高士达，在战场上斩杀了他，乘胜追击，就要围攻窦建德。
后五日，义臣果大破士达，于阵斩之，乘势追奔，将围建德。
After five days, Yang Yichen indeed defeated Gaoshi Da, and killed him on the battlefield. He took advantage of the victory to pursue, and he was going to besiege Dou Jiande.
<s>[INST] Kindly elucidate the central themes in this passage in English: 后五日，义臣果大破士达，于阵斩之，乘势追奔，将围建德。 [/INST] After five days, Yang Yichen indeed defeated Gaoshi Da, and killed him on the battlefield. He took advantage of the victory to pursue, and he was going to besiege Dou Jiande.</s>
Kindly elucidate the central themes in this passage in English: 后五日，义臣果大破士达，于阵斩之，乘势追奔，将围建德。
user
After five days, Yang Yichen indeed defeated Gaoshi Da, and killed him on the battlefield. He took advantage of the victory to pursue, and he was going to besiege Dou Jiande.
assistant