Being held by relegation-threatened Hull has proved to Chelsea striker Nicolas Anelka that the Premier League title race is still wide open.
The Blues could have been four points clear of Manchester United had they won at Hull, but could now be toppled from the summit this weekend by the defending champions.
That would happen if Chelsea loses at home to Arsenal for the second successive season and United beats bottom-place Portsmouth. Even if Chelsea draws, United could go top with victory by three goals or better.
"Things can change very quickly," Anelka said. "If we lose one game and draw one game and Arsenal win two games, then we are back to how it was before. We have to just stay positive and try to win every game."
Making that more likely is the return of Ivory Coast striker Didier Drogba from the African Cup of Nations.
"He is a target man and he plays with a lot of quality up front," Anelka said. "It works well because Didier likes to play in front of goal and I love to play around him, I feel most comfortable in this position these days and it's working well."
Chelsea's 1-1 draw at Hull has lifted some of the gloom engulfing Emirates Stadium after Arsenal's 3-1 loss to Manchester United on Sunday.
Arsenal has spent the season on the back foot, with Arsene Wenger's side left facing an 11-point deficit on Chelsea after collapsing 3-0 to the west London club in November.
Although the Gunners have clawed some of that back, with 14 matches to go Arsenal is on 49 points, behind United on 53 and Chelsea on 55.
"We are on schedule to do good things this season. We have only a little step to get back to the top of the league," goalkeeper Manuel Almunia said. "When you think about where we were after the Chelsea game, that is a great achievement.
"Sometimes it is better to come back from third or fourth to challenge than to be at the top all the time."
The tussle for the Champions League places will be in the spotlight Saturday with fourth-place Tottenham hosting Aston Villa, which is two points behind in seventh.
Liverpool and Manchester City, which are both just a point behind Spurs, will be hoping Spurs slip up. City is at Hull, while Liverpool hosts Everton in the Merseyside derby, with the Reds unbeaten in the league since Dec. 19 following a steady recovery.
"We are close to the top four, which is where we want to be, and the only thing we can promise is we will fight for that to make it happen so we are in the Champions League next season," Liverpool winger Albert Riera said. "We are winning games now. We are more confident and we believe we can be in the top four come the end of the season.
"We are doing better defensively now and not conceding silly goals. At the start of the season when we were giving free kicks away just outside the box, we were not confident. We have worked a lot on that in training and we have improved."
At the bottom of the standings, there is a tight fight against relegation. West Ham, Bolton and Wolverhampton are only out of the drop zone on goal difference at the expense of Hull, which is also on 21 points.
West Ham goes to next-from-bottom Burnley on Saturday when Bolton hosts Fulham, while Wolves is at eighth-place Birmingham in Sunday's lunchtime kickoff.
"The coming weeks are going to be interesting because we've got some games against teams fighting for their lives at the bottom of the league and desperate for points," Birmingham manager Alex McLeish said. "There are some real battles ahead and we've got to be prepared for those."
On Saturday, Wigan is at Sunderland. The Latics are on 22 points, two behind Sunderland.
