Middlesbro - 1 Chelsea - 2 Deeply unconvincing they may have been, buckling at times under a frenzy of home pressure, but Chelsea still hover with menace at Arsenal's shoulder this morning, a point from the Premiership's pinnacle courtesy of Hernan Crespo's unlikely late winner.

So that is what £ 16.8 million can buy.

The Argentinian emerged from the disjointed mishmash - not least of his own performance - to break Boro two minutes from the end, peeling away from Danny Mills and nodding Damien Duff's cross down and beyond Mark Schwarzer at his near-post.

"I honestly don't think we deserved it," admitted the £17 million Irishman.

This was a £33.8 million sucker punch to broaden the beam plastered across the watching Roman Abramovich's face.

Given the Russian's open-chequebook approach, the last thing the rest of the Premiership needed was Chelsea relying on good fortune to win games. Even the Londoners can't buy luck, after all. Yet, having barely broken into a sweat to control and glean a deserved lead in the first half against lethargic opponents, Claudio Ranieri's side creaked alarmingly under Boro's breathless riposte thereafter.

The home side were level within 19 seconds of the second period when the ponderous Robert Huth stumbled on George Boateng's pass and was robbed of possession by Gaizka Mendieta. The Spaniard reflected Boro's mood throughout - anonymous to the point of appearing uninterested up to the break, purring after it - and tore forward into Chelsea territory, slipping a thrill of a pass inside for Szilard Nemeth to finish emphatically beyond the exposed Carlo Cudicini.

The concession was hardly the stuff of potential champions, even for a side whose squad permitted seven changes from the midweek humbling to Besiktas and left £45 million-worth of personnel watching from the bench.

"The table says we are a point behind them, but we are not close to Arsenal or Manchester United in reality," insisted Ranieri. "We are working to close the gap between us and them, but we still need time.

"If you watch Arsenal or United, they know how to slow the tempo down, they have a maturity which we don't yet have. We are still learning. Sure, we have a good fighting spirit, but we still have to improve our tactics. My players never thought it was too easy out there, but we suffered a lot after conceding that goal."

That much was true, with Mendieta so irrepressible that Boro threatened to maraud to a fourth consecutive success. He once cost Lazio £29 million from Valencia and looked the twice European Cup finalist he is, drifting away from the dithering Wayne Bridge to zip a low cross-shot agonisingly beyond the far post, then clipping a marvellous free-kick for Malcolm Christie to chase into the area only for the striker to lift a shot wastefully over the bar.

"You didn't just see quality, technique and ability, you saw attitude and work rate," said Steve McClaren, who watched as Doriva, inspired by the Spaniard at his side, pummelled a volley which Cudicini palmed away before Boateng drilled a shot wide with the Italian beaten.

"You always wonder if they'll adapt to the English game. He (Mendieta) won't have a problem. It's players like that who can win you a football match in a matter of seconds," said McClaren.

That honour had been reserved for Crespo. The former Internazionale striker had been introduced at the interval and, blinded by Boro's pressure, stumbled around the turf as if a little boy lost. When he roused himself to rob Colin Cooper, overplaying on the edge of his area, he could only batter a panicked shot straight into Schwarzer's face with the goal gaping. "He is only playing at 60 per cent," offered Ranieri. "We need to get to know him."

Chelsea will know and appreciate him all the more now, the victory his header earned at the death rekindling the dreamy memory of their first-half swagger. The visitors had been sumptuous from the start, edging ahead when Frank Lampard dispossessed Boateng, Duff spun on to the loose ball and slipped a smart pass inside Mills and Chris Riggott for the unmarked Eidur Gudjohnsen to gather.

The Icelandic striker, unnoticed on the edge of the area, feigned one way, shot the other and ripped his first Premiership goal of the season inside Schwarzer's near post.

When the excellent John Terry headed Lampard's free-kick on to the crossbar with Boro still lulled, it seemed this was to be a victory reminiscent of Arsenal's 4-0 stroll here in August.

"But we are not playing our best football yet," added Duff. "The gaffer has been chopping and changing and we haven't generated any momentum yet, but we still got through this one."

That, more than anything, will have Arsene Wenger and Alex Ferguson fretting.