JAN Vennegoor of Hesselink came off the bench to nod home a stoppage-time equaliser for Celtic in their Algarve Cup opener against Middlesbrough in Portugal last night.

The Clydesdale Bank Premier League champions were heading for defeat when substitute Darren O'Dea's under-hit backpass gifted Jeremie Aliadiere, the Frenchman who endured an ill-starred loan spell at Celtic for a month early in the 2005/06 season, a bizarre opener 19 minutes from time.

O'Dea's ill-advised pass to Mark Brown saw the back-up goalkeeper's attempted clearance charged down by Aliadiere, the ball rebounding off the striker's feet and into the net.

But Vennegoor of Hesselink levelled in the second minute of added time when Bobo Balde headed fellow substitute Paul Caddis' cross back across goal and the Dutchman stooped to nod home.

The result saw both sides claim two points apiece, one for the draw and one for scoring a goal, putting them three points behind Cardiff City, who beat Vitoria Guimaraes 2-1 earlier last night with a double from former Motherwell striker Ross McCormack.

Celtic created the first chance of the game when captain Stephen McManus won possession and fed Mark Wilson. The full-back sent Aiden McGeady down the wing and the Irish international raced past two defenders before picking out Georgios Samaras in the box. The Greek international directed a header goalwards, but Ross Turnbull's save in the Middlesbrough goal denied him his first strike since committing to Celtic on a three-year deal this summer.

Samaras was making his presence felt, chasing down Andreas Hinkel's long clearance and outmuscling David Wheater but again Turnbull was alert to gather the striker's attempted lob.

Middlesbrough took time to get a foothold in the game but enjoyed the better of the final quarter of the first half when Mark Brown, again deputising in goal for Artur Boruc, was tested by Josh Walker, who was on loan at Aberdeen last season.

Then a sublime piece of skill by McGeady, jinking past Luke Young, bought him space to cross for Samaras who was again denied by Turnbull.

Middlesbrough made ten changes at half-time, including the introduction of Aliadiere. He immediately troubled his old team's defence, earning a free-kick from Gary Caldwell, although Andrew Taylor could only send his effort into the defensive wall.

Celtic were on the backfoot until 14 minutes into the second period when Robson won a free kick 30 yards out. The midfielder took it himself, looking for his third goal in pre-season so far, and was only denied by an excellent save from Turnbull.

Gordon Strachan freshened up his team three minutes later, taking Caldwell, McManus and Hinkel off and bringing on Balde, O'Dea and Lee Naylor. Another triple change followed on 67 minutes, Vennegoor of Hesselink, Caddis and Massimo Donati coming on for Scott Brown, Scott McDonald and Robson.

The deadlock was finally broken in the 71st minute, Aliadiere claiming a reward for his persistence. Strachan responded by replacing Samaras with Paul McGowan, while Boro brought on for Tuncay for Walker. O'Dea cleared well as the Teesside club chased a second and McGowan tracked back as Middlesbrough pushed forward on the flank.

In the 82nd minute, Celtic almost equalised after Paul Hartley floated over a free-kick following a foul on Vennegoor of Hesslink, but Donati's shot was blocked. McGeady attempted to pick out the Dutch striker with the rebound but to no avail.

Naylor conceded a corner with five minutes remaining but Balde had little difficulty clearing the danger.

Two minutes before the end, Vennegoor of Hesselink was denied a chance on goal when the referee called play back after the Dutch international had intercepted a Middlesbrough free-kick. The striker, however, was to have the last laugh. A corner was cleared to Caddis, who picked out Balde at the far post. The Guinean headed back across goal for Vennegoor of Hesselink to equalise.

Celtic almost grabbed a winner immediately after the equaliser but neither Caddis nor McGowan could make contact with Hartley's cross.

Middlesbrough: Turnbull, Young (McMahon 46), Pogatetz (Williams 46), Wheater (Huth 46), Grounds (Taylor 46); Emnes (O'Neil 46), Shawky (Digard 46), Arca (J Johnson 46), Walker (Tuncay 77), Owens (A Johnson 46); Alves (Aliadiere 46).

Celtic: M Brown, Hinkel (Naylor 60), Caldwell (Balde 60), McManus (O'Dea 60), Wilson; Robson (Caddis 67), Hartley, S Brown (Donati 67), McGeady; McDonald (Vennegoor of Hesselink 67), Samaras (McGowan 73).

Subs not used: Boruc.