Leyton Orient dumped holders Peterborough United out of the Johnstone's Paint Trophy after an impressive 3-2 win tonight.
The visitors got off to a perfect start after just four minutes when Chris Dagnall headed home the opener. But it was quickly cancelled out when debutant Marcus Maddison fired home for the Posh.
But Orient regained the lead at the start of the second half when Dagnall produced a superb finish for his second of the game. It was 3-1 when Bradley Pritchard back heeled the ball into the net before Romain Vincelot was sent off for a second booking.
Substitute Luke James pulled one back in injury time but Orient held out to book their place in the second round.
Dagnall was handed his first start of the season for the O's in attack. There were recalls for keeper Gary Woods and Shane Lowry following their impressive displays in last week's shock win at Aston Villa.
Jay Simpson missed the trip with his wife in labour while Dean Cox was missing with a knee injury but summer signings Darius Henderson and Jobi McAnuff were both named on the bench.
The O's made an ideal start to the match, which was the first meeting between the sides since Orient won May's play-off semi-final, when Lloyd James sent in a free-kick and Dagnall was left unmarked to head past former Orient keeper Ben Alnwick.
It was almost 2-0 to Orient when David Mooney's header struck the post.
But Peterborough drew level in the 16th minute when they took a short corner and Maddison rifled a shot past Woods.
Jack Payne fired in a speculative effort from distance which troubled Woods and he fumbled the ball round the post for a corner.
Orient regained the lead after 47 minutes when James lofted a pinpoint ball over the defence and Dagnall produced an exquisite volley into the net.
The O's had another opportunity from a free-kick just outside the area but James blasted his shot well over the crossbar.
Russell Slade made his first change when he brought on McAnuff for the excellent James.
Orient extended their lead after 62 minutes when Dagnall sent in a cross and Pritchard back heeled the ball home.
The O's were reduced to ten men with 20 minutes remaining when Vincelot was shown a second yellow card after tangling with an opponent.
League 1 leaders Peterborough almost pulled one back but debutant James was denied when Woods made a fingertip save to keep out his header.
The O's made another late change when youngster Harry Lee came on for Dagnall.
A chance fell to Shaun Brisley but he blasted his shot over the bar before James tucked away a second goal from close range in injury time. But it was too little too late as Orient progressed to the second round of the competition.
Peterborough United: Alnwick; Smith, Brisley, Burgess, Ferdinand (Barnett, 80); Newell, Payne (McCann, 66), Anderson, Maddison; Vassell (James, 61), Washington
Subs not used: Walker, Santos
Leyton Orient: Woods; Cuthbert, Clarke, Baudry, Lowry; Pritchard, James (McAnuff, 61), Vincelot, Bartley; Mooney, Dagnall (Lee, 87)
Subs not used: Legzdins, Henderson, Ling
Referee: K Hill