SO he has won a treble after all.

Some would seek to define the managerial career of Neil Lennon by his failures rather than his successes. It is a universal football trait to dwell on the disappointments rather than exult in the victories but it is condition that is at its most virulent in its Caledonian strain.

It could be categorised as the Aye, But virus. Its symptoms are a myopia to the good and an obsession with the bad. So Lennon is criticised for not winning the treble rather than a treble which his third successive league title constitutes.

The only other Celtic managers to achieve three consecutive title wins are Willie Maley, Jock Stein and Gordon Strachan. Lennon, of course, does not yet merit entry to the Pantheon of Celtic managerial greats but he has cause to ask at least for a place in the lobby.

Any discussion of the 2013/2014 season must, of course, deal with the League Cup defeat by Morton and the William Hill Scottish Cup loss to Aberdeen. The first was so freakish to be almost absurd. The second was the result of an excellent Aberdeen performance.

The philosophical banality that these things happen in football is not likely to be met kindly by fans or rivals. The burden for Lennon is that the domestic treble of league and two cups has suddenly been rendered as something so easily attained as to be almost compulsory. The mere attainment of a title and subsequent entry into Champions League qualifiers is seen by some as a doleful under-achievement.

Yet Lennon has played a crucial role in a testing time for the club. His achievements are substantial. He has led Celtic into the group stages of the Champions League twice and the knockout stages once.

With warnings of financial meltdown after the demise of Rangers, his team has not only paid the bills but posted a profit. And it is his team. The starting XI last night was a Lennon production, save for Scott Brown, an inheritance from Strachan, another of the three-in-a-row club.

The Northern Irishman, too, has built teams while pilferers from other leagues have wandered south with his foundations. Kelvin Wilson, Victor Wanyama and Gary Hooper all departed in the summer, Joe Ledley in January. All were excellent for Lennon but he has replaced them within a budget and with a commitment to maintaining quality.

The Aye, But faction would point to such as Mo Bangura and Efrain Juarez as beacons of Celtic fallibility in the transfer market but this accusation can be rebutted with a litany of names. To restrict to those present at Firhill last night: Fraser Forster, Adam Matthews, Emilio Izaguirre, Virgil van Dijk and Stefan Johansen all look capable of attracting substantial sell-on fees. Leigh Griffiths, too, will score goals, Charlie Mulgrew is a starter for Scotland and Kris Commons will be Player of the Year.

If one of the tests of the quality of a manager is whether he can improve players, Lennon passes with a considerable degree of comfort. He has taken potential and led them into battles against Europe's best.

The Aye, But brigade will point to the drubbings by Barcelona and AC Milan this season. The realists will insist that punching above one's weight is not an enduring quality and entry to the group stages is laudable, even remarkable given the gulf in resources between the Scottish champions and those in bigger leagues.

But Lennon's best qualities as a manager are often overlooked. The first is his insistence on playing with pace and with an emphasis on attack. His full-backs last night, Izauirre and Matthews in the first half, were so far upfield when Forster gathered the ball that they were in danger of being ruled offside.

The second is his ability to motivate players in a league season that has contained only one defeat by Aberdeen. Last season Celtic were prone to slips and carelessness. They have been focused and relentless during this campaign. Lennon has learned. It is what good managers do.

The third overlooked trait is Lennon's determination to give youngsters their chance. He showed this early, promoting James Forrest almost immediately he was given a managerial role.

It was apt that on the night Celtic won their 45th championship and Lennon his third as a manager that Liam Henderson, at 17, scored the second goal that ended any hopes of a Partick Thistle revival.

The five goals gave Lennon his treble on a comfortable night for the champions. His side were never truly stretched, though Lennon guarded against complacency by racing from his dugout after a piece of sloppy play by Efe Ambrose and conducting a impassioned, immediate post-mortem after the loss of a late goal to Christie Elliott.

There was an outbreak of bampottery at the end when a deserved ovation from the support was denied after a pitch invasion by a couple hundred eejits. This was a pity because Lennon and his side deserved a prolonged ovation on a night when the Aye, Buts were rendered speechless, if only for the moment.