The Canadian Paul Tracy, a second-year IndyCar driver, took the victory from pole position - his second this season - but not until he had dealt with a strong challenge at the beginning of the race from Mansell.
Mansell gave Tracy the lead on the long runway front straight - a courtesy he has asked others to extend to him. Then he authoritatively claimed the lead at the first turn, which claimed a number of victims.
On lap 15 Tracy got inside Mansell and passed him. Tracy immediately pulled out a two-second lead, which he extended during the next 70 laps, though sliding off the edges of the runway course from time to time.
After the second round of pit stops, which began on lap 60, the order at the front remained unchanged. Mansell found himself 21.14sec behind Tracy, but a check of his mirrors revealed a charging Fittipaldi.
Mansell injured his right wrist in a freak fall after qualifying on Saturday. He started the race with itheavily strapped and had to change gear 20 times on each of the 85 laps using his right hand.
The heat and a painful wrist began to take their toll, and Fittipaldi was on hand to see what advantage he could take of the Briton's plight.
With 10 laps to go, they traded positions seven times in four laps, ending with Mansell in third and Fittipaldi in second place. The duel gave Tracy a 27- second lead, which he preserved to the finish.
An exhausted but delighted Nigel Mansell said: 'It was some battle out there. It was one of the most exciting races I have ever been in. The great thing is that I was battling wheel to wheel. No one was giving an inch but it was a safe, clean performance. I would like to give Emerson and Paul credit. It was one of the greatest races of my career.'
Emerson Fittipaldi shared Mansell's jubilation over the flawless contest. 'I had an incredible dice with Nigel. Every time I thought I got rid of him he was back again. I'd pass him and he was back again,' he said.
Starting in 12th place, Raul Boesel, who needed a good finish to maintain his threat to Mansell in the championship points race, was caught up in the first-lap incident. He eventually dropped out, leaving Fittipaldi as Mansell's closest championship pursuer, 14 points behind.
BUDWEISER GRAND PRIX OF CLEVELAND INDYCAR RACE Leading placings: 1 P Tracy (Can) Penske-Chevrolet C 127.913mph; 2 E Fittipaldi (Bra) Penske-Chevrolet C +18.09sec; 3 N Mansel (GB) Lola-Ford Cosworth XB same lap; 4 S Johansson (Swe); 5 M Andretti (US); 6 R Gordon (US). Series standings: 1 Mansell 102pts; 2 Fittipaldi 88; 3 Boesel 80; 4 Andretti 75; 5 Tracy 62.Reuse content