LONG BEACH, Calif. -- Green flags 4, red flags 3, yellow and checkered flags 1.

The temporary street circuit for the Toyota Grand Prix of Long Beach bit back during the afternoon session as four cars pushed tire barriers and left paint on whitewashed concrete barriers lining the 1.968-mile, 11-turn course. Retrieval by the Holmatro Safety Team of cars stranded on the course significantly cut into the allotted 45-minute session.

Thirteen laps were the most recorded in the session in which the track temperature reached 131 degrees and the ambient temp hit 84 degrees. Twenty-seven drivers also had 45 minutes of track time in the morning, which wasn't marked by cars sliding into tire barriers and retaining walls.

Click it: Toyota Grand Prix of Long Beach day 1 combined practice results || Qualifying groups

Ryan Hunter-Reay, who won at Barber Motorsports Park two weeks ago and won at Long Beach in 2010, was quickest in the afternoon session with a lap of 1 minute, 09.4224 seconds in the No. 1 DHL car for Andretti Autosport. Mike Conway, making his season debut, was second quick in the session (1:09.4603) in the No. 17 blue eCigs car for Rahal Letterman Lanigan Racing.

"It was a weird day, just never really got a rhythm with the stoppages and the couple of incidents out there," Hunter-Reay said. "I really didn’t get to see who was involved and what happened, but it took a little bit of time out of what we were trying to accomplish with the car. I love Long Beach, always love getting back in the rhythm of this racetrack. Unfortunately Mike likes it, too."

Conway also was second-quick in the morning session, which was topped by Andretti Autosport's James Hinchcliffe.

"Got rid of the cobwebs and the car felt good though we couldn't get a clear run," said Conway, the 2011 race winner. "We got one in, and I think a lot of people they either got one or they didn't get any so we were lucky to just get the one."

Defending race winner Will Power was third quick in the No. 12 Verizon Team Penske car, followed by rookie Tristan Vautier in the No. 55 Schmidt Peterson Motorsports car and IZOD IndyCar Series points leader Helio Castroneves in the No. 3 Auto Club Team Penske car.

"It's very hard to judge lap times though because there were so many red flags," Vautier said. "We're not really sure who got a clean lap in and who didn't. We did make some progress, but I think we have a lot of work to be where we want to be."

Sebastian Saavedra went into the Turn 5 runoff area and spun the car around to rejoin the session. In doing so, the No. 6 Dragon Racing car slid and pushed into a retaining wall nose-first. Soon afterward, Justin Wilson's No. 19 Dale Coyne Racing car slid into the barrier in Turn 8 and was struck in the rear wing by the swiftly moving car of Simona de Silvestro.

"Justin had an incident and was stuck into the wall and there was no yellow flag so I think I was the second car behind him and saw him too late and ran into him," de Silvestro said. "It was a bit unfortunate because I think we were pretty quick and had a few things to try today. We are going to have to try and cram everything in (April 20)."

A few minutes later, Scott Dixon's No. 9 Target Chip Ganassi Racing car smacked the wall on the exit of Turn 9. A few minutes after the session was restarted, E.J. Viso's No. 5 Team Venezuela/Andretti Autosport/HVM car found the tire barrier in Turn 9. The local yellow flag brought an end to the session.

“The Target car wasn’t bad today in the morning session and I think it’s fair to say things were moving in the right direction," Dixon said. "In the second session I just lost it on entry and chased it into the wall."

Another 45-minutes session (1:40 p.m. ET) April 20 precedes the three rounds of qualifications (5 p.m. ET).