Stefan followed up his solid race at Watkins Glen with an excellent fourth place around the streets of Toronto, despite a mishap with a broken seat.

A few days earlier he had headed north into Canada, looking for a strong weekend. "Toronto's one of the tracks I've been looking forward to," he said, "because it's another street circuit, a lot like Long Beach. I've been looking at data and on-board footage and I think we'll have a good set-up there."

His optimism was borne out in the first practice session as he finished third quickest, just over a tenth of a second off the pace set by championship leader JR Hildebrand, and followed up with fourth in second practice. He kept up the momentum in the afternoon, qualifying fifth for the race in a closely fought session which ended with the top 13 covered by less than a second.

On race day morning Toronto was swept by a huge thunderstorm with torrential rain. Happily, by the 12.30pm start time of the Indy Lights race, the weather was calm again and most of the water had drained away. The track was still damp, though, and a wet race was declared, so all the cars had to set out on rain tyres, though it was clear they would need to change to slicks before long.

Off the rolling start the whole field got cleanly through turn one and Stefan settled into fifth position. A few cars pitted early for a tyre change, but Stefan waited till lap 7 along with the majority. It was his first ever pitstop and Indy Lights don't normally do them, so it wasn't a slick F1-style operation, but Walker Racing did a good job and Stefan rejoined the race in the same position as before.

"We pitted for slicks at just the right time and we were really quick straight away when we exited the pits and were probably the fastest car on the track," he said later.

At the front of the field, team-mates Hildebrand and Sebastián Saavedra were well ahead and battling for the lead. James Hinchcliffe was running third and Ana Beatriz fourth. Stefan was challenging hard and on lap 16 he passed her, and from there on he pursued Hinchcliffe until the latter part of the race. "Towards the end the car started to go off and I had a few problems inside the cockpit, so by the last 10 laps there was no way I was going to catch him so I just preserved and kept my fourth place."

Stefan explained afterwards what the "few problems" were: "Coming through turn nine my seat broke and jammed my hand against the interior of the cockpit. I had to drive through the three turns with one hand." While doing that, he managed to get hold of the broken part and throw it out of the car out of harm's way on the pit straight. He took the chequered flag still in fourth place and was happy with that result.