In Chicago he hit six goals in the Sting's inaugural season and firmly established himself as a fan's favorite as did May who despite playing all of his career in the UK as a central defender, was used by Foulkes as a target man scoring 7 times in 18 games which included the winner on his debut in Sting's 1–0 victory over Los Angeles Aztecs, just 24 hours after arriving into Chicago from Welsh club Wrexham.

Also arriving from the UK was Ronnie Moore a prolific striker from Tranmere Rovers, but despite these additions the Sting had a very poor year and Foulkes resigned halfway through the season leaving Willy Roy, his assistant, as interim coach.

This was not the start that owner Lee Stern had anticipated when he brought in Clive Toye as new club president[11] who in turn had hired Malcolm Musgrove as the team's new head coach.

[12] Toye had been one of the men behind the success of the NASL's leading light the New York Cosmos, while Musgrove, a former left-winger with West Ham United was a coach with a growing reputation.

Musgrove had made expensive forays into the transfer market bringing in four new players in the shape of Karl-Heinz Granitza (from Hertha Berlin), Arno Steffenhagen (from FC St. Pauli), Horst Blankenburg (who had played in the great Ajax side of the early 1970s alongside Johan Cruyff, and company) and Jørgen Kristensen (another former Hertha Berlin man).

All number of club records were broken as the Sting scored 70 goals – Karl-Heinz Granitza weighing in with 20 – and the average home attendance increased to a respectable 8,000, 21,000 plus turning out at Wrigley Field to see the New York Cosmos defeated 3–1.

1980: Phil Parkes, the former Wolverhampton Wanderers 'keeper, became the Sting's number 1, moving to Chicago from the Vancouver Whitecaps where he had played for the past three seasons and established himself as the NASL's top glovesman.

Two late goals by the Californian side gave them first blood and a 2–1 win, but the Sting won game two by the same scoreline in front of 21,760 at Comiskey Park.

A crowd of 36,971 – including some 6,000 from Chicago – were on hand at Toronto's Exhibition Stadium and they could have been forgiven for expecting a high scoring game as the two previous meetings between the Sting and the Cosmos that year had produced fifteen goals.

Despite that effort, Chinaglia, the NASL's all-time leading scorer, was marshaled well by the defensive partnership of Frantz Mathieu and Paul Hahn, supply from the flanks by the Cosmos wingers was kept to a minimum by Dave Huson and Derek Spalding, the Sting's two fullbacks, while in goal Dieter Ferner put in another exemplary shift.

New York took the lead after three rounds through Vladislav Bogicevic, Karl-Heinz Granitza then leveled things up before Ferner made a great save to keep out Ivan Buljan's chipped shot.

Joint captains Ingo Peter and Spalding proudly accepted the Championship Trophy from NASL Commissioner Phil Woosnam to confirm the Sting as the North American Soccer League champions for 1981.

A then record attendance for an indoor soccer game in North America of 19,398 saw the Sting come from 8–4 down to beat the Rowdies 10–9 in sudden death overtime.

It was against the Roughnecks that the Sting made an unexpected and early exit from the playoffs having been widely tipped to add the indoor crown to the Soccer Bowl trophy won the previous summer.

[16] Karl-Heinz Granitza finished the season as the league's second highest scorer (behind Julie Veee of the San Diego Sockers) with 35 goals and 36 assists.

The Sting had sufficient players to do so but was left with a surfeit of foreign stars and David Huson and John Tyma – who had both played their part in the 1981 success – were traded to other teams.

The first win of the season came against the Tulsa Roughnecks at Wrigley Field on May 1 but that was just a brief respite as the Sting slumped to a further four defeats to end the month with a 1–7 record.

Then remarkably Frantz Mathieu – a firm fan favourite – was traded to the Montreal Manic, with Gordon Hill coming the other way, making his return to Chicago after a seven-year absence.

After holding Nacional of Uruguay to a 0–0 tie and defeating Italian Seria A side Napoli 3–1 they lifted the trophy with a 4–3 victory against the New York Cosmos in front of 36,904 at Giants Stadium, New Jersey.

Defensive mistakes, poor officiating and continuing injury problems dogged the remainder of the season although the Chicagoans did manage a run of three straight wins to briefly keep alive hopes of making the playoffs.

Chicago goalkeeper Victor Nogueira was impressive in both matches, especially in the final minutes and the Sting held on to win their second title in four years.

Toye followed that up by taking verbal jabs at Roy and Granitza in the press, referring to them as "cheats" and the Sting as "unworthy champions"[20] among other things.

In the end the lack of sportsmanship mattered little, as Chicago walked off into the sunset with the trophy and the NASL ceased operations the following year with Toye as its interim president.

[21][22][23][24] 1985–86 (Indoor): The season kicked off with the Chicago Sting able to boast that they were the oldest existing professional soccer franchise in the United States.

Head Coach Willy Roy, who had led the Sting to two NASL titles, was replaced by his assistant Eric Geyer in late December, and Karl-Heinz Granitza, the club's all-time leading goalscorer, who at the beginning of the season had seen his annual salary cut by $100,000 to $65,000, was suspended indefinitely on March 21 after an argument with owner Lee Stern.

Meanwhile, owner Lee Stern entered discussions with representatives of Halo Advertising Specialties that would see them initially become a minor shareholder but have a controlling interest in the franchise within two years, although this ultimately came to nothing.

[25] In 1988, Lee Stern stated after a leading 7-2 and finishing out on the bottom of the score card with a 8–7 loss against Kansas City that he would sell the team for a nickel.

[29] A few weeks after the end of the 1987–88 season, in July 1988, owner Lee Stern announced that the Sting had withdrawn from the MISL, citing falling attendances, failure to find new investors and concerns that the league was on the verge of collapse.