Boston United joint-manager Lee Canoville felt poor defending led to their 4-2 FA Trophy defeat by Dartford.
Jacob Erskine netted a hat-trick for the Blue Square Bet South side while Spencer Weir-Daley and Leon Constantine were on target for the Pilgrims.
Canoville told BBC Lincolnshire: "I'm pleased that we scored two goals and had a go, but we conceded three goals from two long throws and a set-piece.
"They're silly goals that have cost us because we felt he had a chance today."
Dartford took the lead after four minutes through Erskine but the Pilgrims levelled when Weir-Daley, in his first appearance since rejoining the club, turned home Tom Ward's header following a 21st-minute Ian Ross corner.
Erskine restored the hosts' lead early in the second half, scoring from Lee Noble's cross after a quickly-taken throw, and Noble made it 3-1 with a close-range effort on 61 minutes.
Substitute Constantine looked to have ensured a tense finale with a header eight minutes from time but Erskine put the tie beyond doubt in the 90th minute, turning home a free-kick for his hat-trick.