A record 3,209 crowd at the Flamingo Land Stadium enjoyed a fabulous cup-tie, writes Steve Adamson.
Fortunately the pre-match downpours stopped by kick-off, both teams making changes from recent games. Ryan Whitley returned in goal for Boro, Bailey Gooda making his first start in six games, and Alex Wiles back after missing three matches with a thigh injury, while three Rovers first-teamers were out injured.
The bumper crowd was in great voice throughout, and the hosts gave them plenty to cheer as they more than matched their full-time opponents.
Teddy Jenks dragged a shot wide for the visitors in the third minute, but Boro took control of midfield, Luca Colville, Alex Purver and Lewis Maloney all on top form, and when Alex Brown was fouled by Jenks, Maloney curled a 25-yard free-kick narrowly over.
Frank Mulhern had a volley charged down by Jamie Robson, and Maloney laid off to Wiles, whose shot was blocked by Harvey Bunker.
Chances for Forest Green saw Jenks fire wide and Reece Welch sent a through-ball to Jacob Maddox, with Whitley easily saving his scuffed shot.
Boro played some terrific football, with Purver, Wiles and Colville involved in a lovely sequence of one-touch passes, while the central defensive trio of Gooda, skipper Will Thornton and Ryan Qualter was strong and solid, winning some crunching tackles and most of the high balls.
The deadlock was broken on 27 minutes with a fabulous goal, when Kieran Weledji battled for possession on the right and passed forward to Mulhern, who laid off to Wiles just inside the area, and he showed nimble footwork to shrug off the challenge of two defenders, and slot into the bottom left corner.
Charlie McCann sent a free-kick just over the bar, Qualter’s diving header cleared a cross into the goalmouth from Jenks, and Whitley plucked a Maddox cross of the head of Robson as Forest Green tried to fight back, then Sean Robertson sent a long-range shot wide, but Boro almost doubled their lead when Weledji burst into the box and his fierce shot forced a superb save out of James Belshaw.
The visitors had lots of possession in the second half, but Boro defended stoutly while looking dangerous on the counter-attack.
The pacy Tyrese Omotoye headed straight at Whitley then Thornton’s tackle halted an Omotoye charge forward.
The visitors twice went close, Omotoye firing a volley narrowly over, and Jacob Maddox side-footed inches wide, then Maloney’s through-ball sent Michael Coulson clear for Boro, but keeper Belshaw smothered his shot, and Maloney had a strike blocked by Bunker.
Whitley did well to save a fierce low shot from Nathan Holland, and as the final whistle loomed, Colville and Dom Tear combined to send Coulson into the box, but he was closed down before he could get in a shot.
Boro seemed to be heading into the next round, but with just seconds remaining, a ball forward found McCann inside the Boro area to the right of goal, and his first time pass into the goalmouth was stabbed home from close-range by 18-year old Olly Sully, who had scored a hat trick for the youth team in midweek.
In just his second first-team appearance, his sensational late goal earning his side a replay, and denying Boro the win that their battling performance surely deserved.
BORO - Whitley, Weledji, Brown, Gooda, Thornton, Qualter, Purver, Maloney, Mulhern (Coulson 73), Wiles (Tear 66), Colville
FOREST GREEN - Belshaw, Bernard, Bunker, Welch (Holland 63), Robson, McCann, Jones (Bendle 87), Maddox, Jenks (Sully 81), Robertson, Omotoye
REFEREE- Marc Edwards
GOALS - BORO - Alex Wiles 27; FOREST GREEN - Olly Sully 90
CORNERS - BORO 5 FOREST GREEN 1
YELLOW CARDS - None
BORO MAN OF MATCH - Bailey Gooda
ATTENDANCE - 3,209 (155 away)