Batman so happy that Robben is by his side

Kezman's confidence is natural, given his prodigious goal-scoring feats, but also springs from a deep-seated religious conviction. In Holland he celebrated every goal by removing his shirt to reveal a Jesus logo, his way of thanking God for all his goals.

PSV fans christened their hero Batman and played the Caped Crusader's theme tune after each of his 28 goals last season, a possibility Chelsea are also considering. Kezman seems slightly bemused by his unlikely nickname but it's surely better to be compared to Batman than Arkan, a rather less celebrated Serbian hitman.

Kezman said: "At PSV they played the Batman song and sold a lot of shirts, so it was a good financial decision. After every goal they played the theme tune and if I score a lot of goals here, then they should do the same.

"I'm a very religious guy and Jesus is always with me. He gives me power in all aspects of my life, giving me a quiet life with a nice family. I know how lucky I am."

Kezman played as a lone striker against Celtic, with Mourinho adopting his preferred 4-3-2-1 formation, but can operate in several positions. Equally at home behind a central striker or wide on the right, Kezman's flexibility will make him a key player for Chelsea this season, and his partnership with former PSV colleague Arjen Robben is a fascinating prospect.

Holland international Robben made an immediate impact on his Chelsea debut on Saturday, creating the second goal for Eidur Gudjohnsen just five minutes after coming on as a second-half substitute. But it is his reunification with Kezman that really quickens the pulse. Batman and Robben are back together again.

Kezman said: "Myself and Arjen are very good friends. We played together at PSV for two years and spoke to each other a lot, both inside and outside the dressing room. We talk every day and it's fantastic for Chelsea that he's here.

"It's very good for me because I know how he plays and our communication is excellent. I hope he's going to create a lot of goals for me this season. At PSV he created about 10 or 15 goals for me each season and I'm sure it'll be the same at Chelsea."

Robben failed to create a goal for his friend against Celtic but Kezman still got on the scoresheet twice to kill off Celtic's fightback in front of a reasonable crowd of 30,504.

Alexei Smertin, who impressed as the central pivot of a midfield three, gave Chelsea the lead with a left-foot drive from 25 yards before Robert Huth showed why Mourinho is still looking for another centre-back, as the young German's lack of pace enabled Craig Beattie to equalise.

Beattie grabbed a second after Gudjohnsen and Kezman had given Chelsea a 3-1 lead but the Serbian had the final word, taking advantage of Glen Johnson's through-ball to seal a 4-2 victory. There should be plenty more where that came from.