Complex sentence: After the Belmont, he easily won the Haskell Invitational on August 2 but three weeks later, he finished a close second in a hard-fought Travers Stakes at Saratoga Race Course on August 29,2015, snapping a winning streak of eight races.
Split into simpler sentences: After the Belmont, he easily won the Haskell Invitational on August 2. On August 29, he finished a close second in a hard-fought Travers Stakes at Saratoga Race Course, snapping a winning streak of eight races.