Chelsea ensured they kept up the pressure on leaders United thanks to Michael Essien's first-half winner against Manchester City at Stamford Bridge today.

It put the Blues back into second place, ahead of Liverpool on goal difference, and just four points behind United.

But Hiddink was still extremely wary of United's game in hand on the rest of the chasing pack.

"If it was just four points it would be very close, but they have that game in hand," he said.

"But it's clear that after yesterday's unexpected result that the tension has come back in the league.

"It's a boost. But if we want to track them, we have to keep on winning. That'll give tension to the end of the season, which is good for everyone.

"Every now and then you get a defeat you don't expect. Sometimes you don't expect it at home because you have a beautiful record, then all of a sudden it happens.

"But they're a very experienced team. Let's see how they react in the up-coming days. It's not the first time that it's happened, but the big teams always react.

"I don't know what their reaction will be. When you are in the driver's seat and someone else is coming, you can get a little bit nervous. It is a little bit open now."

Hiddink, who has agreed to remain as Chelsea coach until the summer, likened himself to a "schoolboy" when it comes to the task of chasing experienced campaigners like Rafael Benitez and Sir Alex Ferguson.

But the Dutchman insisted the title would be decided by the players and not the managerial personalities.

"It's not a battle between the managers," added Hiddink. "It's a battle between the players.

"They're both very experienced - Rafael is experienced and Sir Alex is very experienced. Let me, as a schoolboy, chase them. At the end, it's the players.

"We can improve. Today we were solid defensively and were not under threat from City, but I'd have liked us to have finished it off in the first half.

"If we'd scored the second, it might have been a 4-0 game. We have to finish them off. That's the only criticism we can have."

City boss Mark Hughes found himself having to justify the disappointing performances of both his team and £32 million Robinho.

City failed to trouble Chelsea goalkeeper Petr Cech all afternoon and Hughes put much of his side's poor display down to the lack of preparation time following their midweek UEFA Cup participation.

"It's sometimes difficult away from home," said Hughes. "It was difficult to get him into the game. You have to give the opposition credit for that because they see Robinho as a threat for us and they're going to try and deny him the space to have a positive impact.

"You can't just expect one player to carry the team. We have other players who have to stand up to the plate and be counted. Today wasn't Robinho's day.

"His general performances have been good. He's scored 11 Premier League goals and had a real impact for us.

"It's been more difficult for us to get him in the right areas to score, but he's created a number of goals for us and is helping the team. Today was just one of those days when he wasn't able to have a positive effect on the side.

"He is under pressure every time he plays and there's an expectation every time he plays. But all our attackers struggled so it is unfair to pinpoint him.

"Our attacking play was maybe a little too slow. We're an attack-minded team, but we didn't have that sharpness that you need when you come up against one of the top sides.

"I just think we looked a bit leggy today. The difference in preparation time told in the end. The fact that we were missing key personnel as well didn't allow us to have that spark or dynamic play we've had in recent weeks.

"We switched off briefly for the goal we conceded. At that point, Chelsea were quite comfortable to protect that lead, and we didn't ask enough questions of them because we lacked that spark."