When West Ham visited Chelsea in January it was a turning point in their fight for Premier League survival. Now Sam Allardyce has warned Jose Mourinho: "We'll see what century we're in."

West Ham beat Leicester 2-0 on Saturday to ensure they will be fourth on Christmas Day in their best start since the 1985-86 season, when they ended up finishing third.

Matches at Chelsea and Arsenal in the space of three days will be a fierce examination of a rejuvenated West Ham, who were accused by Mourinho of playing defensive "football from the 19th century" when drawing 0-0 at Stamford Bridge at the start of the year.

"The turning point, why West Ham United stayed in the division eventually, was the draw at Chelsea," Allardyce said.

"That's how important it was. It gave the lads a huge confidence boost and huge belief that they could hold a team like Chelsea off.

"We went from there on to make ourselves safe in the league.

"We'll see what century we're in when we finish there (on Boxing Day).

"It's a nice time, I think, for us to be playing Chelsea and Arsenal.

"We can go there and see if we can go and challenge ourselves against two of the big boys in this league.

"If we don't, it's not going to be too much of a knock back for us, because we know we can catch it up by beating teams who are below us, like Leicester."

Stewart Downing, playing at the tip of a midfield diamond, has been key to the Hammers' best Premier League start.

"He's probably playing his best football ever at the moment," Allardyce said.

"It took a bit of persuading to get him here from Liverpool [in August 2013]. It really was a dream move for him that didn't work quite as well as he would've liked.

"He's come here and started showing great class and great ability."

Allardyce confirmed West Ham are aiming to sign Canadian defender Doneil Henry, who is under contract with Cyprus' Apollon Limassol.

Henry was recommended by Ryan Nelsen, who played under Allardyce at Blackburn and managed the defender at Toronto.