Complex sentence: Nizhnyk got a winning position, but oversaw a combination by Vocaturo that allowed a perpetual check, the draw being sufficient for Vocaturo to maintain his half point lead and win the tournament.
Split into simpler sentences: Nizhnyk got a winning position but oversaw a combination by Vocaturo that allowed a perpetual check. The draw was sufficient for Vocaturo to maintain his half point lead and win the tournament.