A hat-trick from former Boro midfielder Jimmy Beadle helped West Pier battle back for a 4-3 home win in their NRCFA Saturday Challenge Cup quarter-final at home to Redcar Athletic Reserves.
Andy Spivey's troops were not on top form but still managed to make the early chances with Tommy Barker hitting the post with an early shot and having an effort cleared off the line.
Niall Gibb then found the net, but unfortunately he put it in his own net to give Athletic the lead.
Beadle's tame long-range shot took a wicked deflection to level the scores for Pier but the Teessiders regained their lead in the 34th minute when they took advantage of some poor marking by the home defence.
A neat turn on the edge of the box and a fine strike by Neil Thomas brought the scores level heading into half-time.
After the interval Pier were dominant, but it was the away team who took the lead for the third time in the cup-tie.
Man of the match Beadle tapped in from close range to bring Pier back on terms again and then scored with a similar effort to net them a place in the final four.
Spivey said: "We are into the semi-finals for the third time in five years but it was not pretty today."
Edgehill will not be joining them in the final four as they slumped to a 2-0 loss at Great Ayton United Royals.
A goal in each half was enough to knock the visitors out of the cup, with Edgehill boss Steve Clegg regretting not having his full side for the cup-tie.
He said: "We had a few players missing today, but despite this we had the better of the opening exchanges and when they scored on the half-hour it was probably their only shot of the first half, and then we missed an open goal.
"Lloyd Henderson was head and shoulders above the rest, he was our man of the match, starting at centre-back and then moving into midfield."
Filey Town suffered a controversial 4-3 loss at Walkington in the ERCFA Senior Country Cup quarter-finals.
The host raced into a 4-0 lead by half-time but the Scarborough League side roared back to pull it back to 4-3 in the second period thanks to goals from Daz Clough, 18-year-old Callum Gravestock and a stunning volley from Tom Micklethwaite.
The visitors were then denied a penalty and also had a goal not given when it seemed to be well over the line, Walkington hanging on for the win.
Angry Town chief Dave Brannan said: "The referee turned down what was a clear penalty, which would have made it 4-4 and then we had a goal disallowed when it was two foot over the line, even their lot was admitting that after the match.
"We have to blame ourselves for giving away the goals in the first half, but it is very frustrating when decisions go against you like that in the cup."
Third division Goldsborough United pulled off a shock 2-1 win at Division Two leaders Filey Town Reserves in the League Trophy quarter-finals.
Max Gage put the home side in front after 15 minutes, and they held onto this lead until the half-time break.
Mike Dent scored from a corner to bring the scores level and then Richard Davies won it with a cracking solo effort, racing 20 yards with the ball before hitting a 20-yard screamer into the top corner of the net.
Tom Kilpatrick was named as the man of the match for the victors.
Scalby joined United in the final four after their 2-1 home win against fellow second division side Goalsports.
Rob Speight opened the scoring for the hosts with a cracking finish after racing onto a long ball, the visitors paying the price for missed chances by Tyson Stubbings.
The visitors improved after the interval but they could not stop Speight striking again in the 55th minute, debutant Sam Pallant firing in a goal to give Goalsports hope in the 75th minute.
Dan Pollard's strike hit the bar for Goalsports, a Scalby defender hit his own bar and then Dan Pickard headed over with an open goal to aim at in the final move of the match.
James Blenkinsopp was man of the match for the victors after a solid performance in defence, while Pallant impressed for the away side, starting on the right flank before switching to central midfield.