London - Nicolas Anelka scored a superb second-half hat- trick as Chelsea came from behind to beat Watford 3-1 in the FA Cup on Saturday.

Tamas Priskin had put Championship side Watford ahead at 69 minutes but French striker Anelka, with new Chelsea manager Guus Hiddink watching from the stands, scored twice in two minutes (75 and 77).

Anelka then completed his hat-trick in injury time to seal his side's place in the last eight of football's oldest club competition.

Blackburn Rovers needed a last-minute goal to avoid an upset as they salvaged a 2-2 draw at home to Coventry City, while Fulham and Hull City will both require replays. West Ham United came from behind to force a 1-1 draw with fellow Premier League side Middlesbrough.

Assistant manager Ray Wilkins took charge of the Chelsea team in name, but with Hiddink, who has taken over from Luiz Felipe Scolari until the end of the season, observing, the players all wanted to put on a show for the Dutchman.

With Didier Drogba looking like a new man, the visitors began well. He set up Anelka for a shot in the first half that hit the post. At the other end, Jobi McAnuff was causing problems for a defence that was missing the suspended John Terry.

Chelsea continued to dominate possession into the second half. But it was the introduction of Hungarian substitute Tamas Priskin that gave Watford the lead. Released down the left, Priskin brilliantly chipped Petr Cech to send the home fans wild.

With 20 minutes to go, a massive upset looked a real possibility, but Anelka had other ideas. First, on 75 minutes, he hooked in a corner to level the scores and then, one minute later, he headed Ashley Cole's cross into the bottom corner.

And after Watford had gone close to an equalizer, Anelka made it 3-1 with his third goal, finishing off Salomon Kalou's pass to seal the victory.

At Ewood Park, it looked as if Coventry would get the better of Rovers for the second successive season. But a mistake in the dying seconds cost the Championship side dear.

Roque Santa Cruz gave the home side the perfect start with the opening goal after just two minutes, but Aron Gunnarsson volleyed a fine equalizer on 61 minutes and Michael Doyle put the visitors ahead 14 minutes from time.

But with time running out, stand-in goalkeeper Andy Marshall could not hold a shot from Keith Tracey and Christopher Samba fired in the rebound.

"I have got no problems with the result. I just have a bit of a problem that we cannot see teams off when we have an opportunity," Blackburn manager Sam Allardyce said.

"We have started to ship too many goals at Ewood and that is becoming one of our Achilles heels."

Jason Scotland scored his 12th goal in 12 games to force a replay for Championship side Swansea City after their 1-1 draw with Fulham.

Fulham took the lead just before half-time through an own goal by Swansea captain Garry Monk, but Mark Gower found Scotland, who fired an excellent equaliser into the bottom corner.

"Sometimes you don't get the results your performances deserve and today was one of those days. We were the better side by miles," Swansea manager Roberto Martinez said.

"We scored a good goal and can take a lot of positives from a game against a side from the Premier League that is in the right end of the table.

"But you need to win when you play like that, no matter who you are playing against."

Kamil Zayette scored the equalizer as Hull drew 1-1 at Sheffield United, while West Ham had Herita Ilunga to thank for their goal in a 1-1 draw at home with Middlesbrough.

On Sunday, favourites Manchester United travel to Derby, while Everton play Aston Villa. (dpa)