Jem scores but Watford win
- Abdi strike gives hosts 1st min lead
- Vydra slams home second before HT
- Deeney converts close range third
- Captain Karacan scores superb effort
- Forestieri adds a late fourth
Almen Abdi scored in the very first minute of the game to give the promotion-chasing hosts the lead, before his replacement Fernando Forestieri set up Matej Vydra for a second before the break.
Troy Deeney put the result beyond doubt when he sidefooted home a third early after the restart, but Jem Karacan came off the bench to take the captain's armband and score a lovely goal from the edge of the Hornets box, pulling one back.
Forestieri added gloss to the scoreline when he found a way past Mikkel Andersen with a powerful low drive that made if 4-1 late on. The Royals now look to Monday's cup quarter-final at Madejski Stadium.
Watford: Gomes; Motta, Ekstrand, Cathcart, Pudil; Watson, Guedioura (Layun 59), Tozser; Abdi (Forestieri 7); Vydra (Angella 85), Deeney (c).
Subs: Bond, Doyley, Paredes, Anya.
Reading: Andersen, Keown, Travner, Cooper, Knight (Novakovich 86), Guthrie, Akpan, Taylor (Karacan 61), Stacey, Cox (c) (Blackman 61), Yakubu.
Subs: Lincoln, Long, Kuhl, Edwards.
Att: 16,660 (1,008 away)
It took lees than a minute for the home side to break the deadlock and open the scoring at Vicarage Road. On the early attack, the ball was fed into the feet of Almen Abdi who drilled a well-struck effort inside the bottom left corner to hand the Hornets an early advantage.
Abdi's afternoon didn't last much longer, making way for Fernando Forestieri five minutes later, but Watford almost got a second when Motta lofted the ball over Yakubu and raced onto the ball before unleashing a powerful strike that hammered into the crossbar.
At the other end, Jack Stacey almost got on the end of a nice throughball only for Gomes to beat him to the ball, and referee Darren Bond dismissed a couple of good appeals for fouls in and around the Watford box.
Then the visitors' first corner was won in the air by Cooper, then Stacey headed it up high for Akpan to scrap with Gomes and a host of Hornets bodies for a decisive touch. Watford cleared eventually though and Taylor couldn't recycle it on the far side.
Deeney's defelcted shot needed a hurried clearance in the Royals area, then Yakubu forced Gomes into a smart save low to his right after the Nigerian pulled the trigger from 25 yards out.
Andersen bettered that with a superb reaction save to palm away an acrobatic overhead from Forestieri with nearly half an hour played, then Taylor ran onto a good ball in behind the Watford defence but hooked a speculative effort harmlessly wide.
Daniel Toszer's high foot on Akpan handed Reading a free kick in a dangerous area, but Yakubu's arced effort was easily dealt with by Gomes.
But with little more than five minutes of the first half remaining, Watford got a second when Forestieri's quick feet carved out an opening for Matej Vydra who smashed past Andersen from close range.
The second half began much like the first with an early Watford goal that put any hopes of a Reading comeback to bed. Forestieri scampered onto a neat one-two down the left and pulled the ball back to the edge of the six yard box where Troy Deeney met it first with a firm sidefoot home.
On the hour, Jem Karacan came on and with Simon Cox making way for Nick Blackman at the same time, Cox handed Jem the captain's armband to give the club captain the chance to skipper the side for the first time since his appointment as captain in the summer.
Reading came close to pulling one back when Niall Keown connected well with Guthrie's corner and Gomes had to stretch high to tip the ball over his bar.
And from the subsequent corner, the Royals did get their goal. And the visiting fans celebrated it like the winner because of the man who scored it. The ball dropped to the edge of the area for Karacan, who controlled it onto his right boot and then brilliantly picked his spot to cur it past Gomes and inside the right post.
Gomes flapped at another Guthrie corner with 12 minutes remaining and then the midfielder fed a reverse ball into the feet of Yakubu who's shot was easily saved by the Watford keeper as Reading pressed for a second.
And the Hornets had taken their foot off the gas, when Blackman almost got in on goal only to be muscled off balance as he shot wide with seven minutes left.
But in the dying stages the impressive Forestieri capitalised on a mistake at the back to add a fourth, rifling past Andersen to make it 4-1. The final whistle sounded and Royals fans could look forward to an FA Cup quarter-final at Madejski Stadium.